Exhibits A through K to the California Coastal Commission

STATE OF CALIFORNIA—THE RESOURCES AGENCY ARNOLD SCHWARZENEGGER , GOVERNOR

CALIFORNIA COASTAL COMMISSION 45 FREMONT, SUITE 2000 SAN FRANCISCO, CA 94105- 2219 VOICE AND TDD (415) 904- 5200 FAX ( 415) 904- 5400

24 July 2006

GEOTECHNICAL REVIEW MEMORANDUM To: Meg Vaughn, Coastal Program Analyst From: Mark Johnsson, Staff Geologist Re: LCPA HNB-MAJ-LCPA1-06 and CDP 5-06-021 (Shea Homes) With regard to the above-referenced project-driven LCPA and CDP application, I have reviewed the following documents:

1) Hunsakers and Associates 1997, "East Garden Grove - Wintersburg Channel (C05) 100-year inundation study for Tract 15377 & 15419, City of Huntington Beach", 9 p. hydrologic report dated 18 August 1997 and signed by S. E. Barnhart (CE 25167).

2) Hunsakers and Associates 1998, "Hydrology and hydraulic analysis for

Tract 15377 & 15419, City of Huntington Beach", 4 p. hydrologic report dated 10 March 1998 and signed by S. E. Barnhart (CE 25167).

3) Pacific Soil Engineering 1998, "Preliminary geotechnical investigation,

Proposed residential development, Tentative tract 15377, City of Huntington Beach, California and tentative tract 15419, County of Orange, California", 36 p. geotechnical report dated 2 February 1998 and signed by T. Wolfe (CEG 1626), M. and J. B. Castles (GE 192).

4) Pacific Soil Engineering 1999, "Response to comments pertaining to

Parkside Estates EIR #97 Draft Environmental Impact Report, Tentative Tract 15377, City of Huntington Beach, California", 26 p. report dated 29 July 1999 and signed by M. F. Mills (CEG 994), J. B. Castles (GE 192) and T. Wolfe (CEG 1626), M.

5) Jordan, N.M., 2000, Diffusion Hydrodynamic Model: Using DHM

rainfall-runoff output to estimate urban watershed existing condition hydrology: Journal of Floodplain Management, v. 1, p. 11-14.

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Application Number: HNB-MAJ-1-06 California Coastal

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6) Pacific Soil Engineering 2001, "Response to draft EIR comments, Parkside Estates, Tentative Tract 15377, City of Huntington Beach, California", 8 p. report dated 11 October 2001 and signed by J. B. Castles (GE 192).

7) Pacific Soil Engineering 2001, "Response to City of Huntington Beach

regarding final EIR, Parkside Estates, Tentative Tract 15377, City of Huntington Beach, California", 3 p. report dated 12 October 2001 and signed by J. B. Castles (GE 192).

8) Pacific Soil Engineering 2002, "Response to City of Huntington Beach

comments on Response to EIR Comments Document, Parkside Estates, City of Huntington Beach, California", 4 p. report dated 13 June 2002 and signed by J. B. Castles (GE 192).

9) Exponent 2002, "Consolidated report, FEMA submittals, detailed flood

Insurance Study, Shea Homes Parkside Estates, Tentative tract Nos. 15377 & 15419, Expanded watershed analysis of East Garden Grove-Wintersburg Channel watershed from tide gates to I-405 freeway", 78 p. report dated 10 August 2002 and signed by Exponent.

10) Pacific Soil Engineering 2003, "Results of groundwater constituent

testing, Parkside Estates Project, City of Huntington Beach, California", 1 p. report dated 5 August 2003 and signed by D. Obert and J. B. Castles (GE 192).

11) Pacific Soil Engineering 2004, "Summary of required grading

operations and construction monitoring requirements, Parkside Estates, Tract 15377, City of Huntington Beach, California", 8 p. report dated 15 January 2004 and signed by J. B. Castles (GE 192).

12) Pacific Soil Engineering 2005, "Transmittal of additional information,

temporary slope stability calculations, Parkside Estates, Tract 15377 in the City of Huntington Beach, California", 1 p. letter report to Mark Johnsson dated 26 April 2005 and signed by J. B. Castles (GE 192).

13) Exponent 2005, "Shea Homes topographic and displacement analysis

with FEMA UNET Model", 7 p. report dated 18 May 2005 and signed by N. M. Jordan (PE).

14) Exponent 2006, "Correlation and frequency analysis of groundwater at

Parkside Estates", 15 p. Technical memorandum dated 22 February 2006 and signed by N. M. Jordan (PE).


Application Number: HNB-MAJ-1-06

15) Exponent 2006, "Frequency analysis of precipitation and ponding at Parkside Estates", 16 p. Technical memorandum dated 22 February 2006 and signed by N. M. Jordan (PE).

California Coastal Commission

16) Exponent 2006, "Summary response to Coastal Commission questions on flood control hydrology and hydraulics", 10 p. Technical

Shea Homes page 2 24 July 2006

memorandum dated 24 March 2006 and signed by N. M. Jordan (PE 44012).

I also have reviewed and commented on the draft Environmental Impact Report (EIR), and have reviewed the final EIR. In addition, I have had numerous meetings with the project proponent’s technical consultants, especially Jim Castles and Mike Mills (geotechnical consultants with Pacific Soils Engineering), Neil Jordan (hydrologic consultant with Exponent), and Steve Barnhart (hydrologic consultant with Hunsakers and Associates). I have discussed hydrologic aspects of the project with Robert Riggetts of the City of Huntington Beach Public Works Department. In addition, I have visited both the subject site and the surrounding neighborhoods on several occasions. This memo represents a review of both geotechnical and hydrologic issues raised by the proposed project. Geomorphology of the site The majority of the Parkside Estates site lies in the lowlands between Huntington Mesa and Bolsa Chica Mesa, known as the Bolsa Gap. In the recent geologic past, these lowlands, like the lowlands between Huntington Mesa and Costa Mesa, were occupied by the ancestral Santa Ana River, which shifted its position across these broad, low plains. Prior to channelization of the river and the construction of the East Garden Grove-Wintersburg Flood Control Channel, these lowlands constituted the broad floodplain of the lower Santa Ana River. Although the site is considered a floodplain geomorphologically, the levees associated with the East Garden Grove-Wintersburg Flood Control Channel prevent it from serving as a functional floodplain today. The northwestern corner of the property is crossed by a bluff, approximately 40 to 50 feet high, carved by the ancestral Santa Ana River. The portion of the site that is to be developed is a very flat surface at an elevation of one to two feet below sea level. The site is underlain by 150-200 feet of very young marine and alluvial deposits, which are underlain unconformably by shallow marine sandstone, claystone and siltstone of the Pleistocene San Pedro Formation. Geotechnical Issues



Commission

Geotechnical issues associated with the proposed project include ground shaking during a major earthquake on a nearby fault, possible surface rupture of the hypothesized Bolsa-Fairview Fault, liquefaction during such an earthquake, inadequate foundation support, the stability of both natural and temporarily excavated slopes, and tsunamis. Because the tsunami hazard is closely related to other hydrologic issues, I will discuss tsunamis in the “hydrology” section of this memo.


Direct Seismic Hazards The active Newport-Inglewood fault passes approximately 2000 feet south of the site. An earthquake along this fault would likely result in severe ground shaking and liquefaction of the soils at the site. The ground shaking hazards can be partially mitigated for by adherence to the Uniform Building Code given the design parameters outlined in reference (3), and the liquefaction hazard is discussed below. Although no unequivocally active faults cross the site, the California Department of Water resources did map a strand of the Newport-Inglewood Fault across the site in 1968, and dubbed the strand the Bolsa-Fairview Fault. According to reference (3), the fault was located only indirectly on the basis of topographic expression, vertical offset of the base of the Bolsa aquifer, abrupt water quality changes between closely spaced wells, limited sea water intrusion northeast of the fault, and pumping test data. Accordingly, the State Geologist identified the fault as potentially active, and it was zoned as a Special Study Zone under the Alquist-Priolo Act. More recent studies by the California Division of Mines and Geology concluded that there was insufficient evidence to indicate that the fault was either active or, in fact, even that it exists, and the State Geologist accordingly de-listed the fault under the Alquist-Priolo Act. The studies undertaken as part of the EIR for the Parkside Estates project failed to yield any evidence for the existence of the fault. Accordingly, although the presence of the fault cannot be ruled out, the indirect evidence put forth by the Department of Water Resources seems insufficient tto warrant the inclusion of the fault as a an identified hazard. Foundation support and liquefaction hazards Reference (8) indicates that the soils at the site are susceptible to liquefaction during a major earthquake. In addition, the presence of peat could lead to settlement problems, because organic materials such as peat are subject to decay and volume loss with time. In order to mitigate for these hazards, Shea Homes proposes to overexcavate the entire site to depths as great as 17 feet below sea level, involving approximately 400,000 cubic yards of cut. Unsuitable fill materials such as peat would be exported, and the remainder of the material—as well as approximately 260,000 cubic yards of imported fill, would be compacted to suitable densities to provide structural support and to be invulnerable to liquefaction.



Commission

Several concerns arise regarding this overexcavation and recompaction. Since the excavations will extend well below sea level, dewatering operations will be necessary. Dewatering will be accomplished through a series of nine wells, 60 feet in depth, that are detailed in reference (11). This dewatering operation has the potential to result in lowering of ground water levels off-site, which could lead to settlement problems. In order to mitigate for this hazard, the excavation will take place in stages, with only narrow excavations open at any one time. In addition, a monitoring program will be in place (detailed in reference 11) to detect any settlement that occurs, allowing time for mitigation efforts. In my opinion, these efforts will greatly reduce the subsidence danger, but that some risk of subsidence of adjacent properties does remain. The


water produced by the dewatering operations will be discharged into the storm water drainage system. Reference (10) demonstrates that this water is suitable for disposal into the ocean. Slope stability The backcuts of the excavations undertaken to mitigate the liquefaction hazard will extend to the Base of the north levee of the East Garden Grove Wintersburg Flood Control Channel. The loss of lateral support for the levee, especially if high pore water pressures persist due to the rapid removal of material in the cut, has the potential to destabilize the levees. Reference (12) contains slope stability calculations that demonstrate that even with the persistence of high pore pressures and loss of lateral support, the slope supporting the levee will have a factor of safety against sliding of 1.28, which is considered adequate for temporary excavations. No slope stability calculations have been performed on the bluff in the northwestern corner of the site, and it is likely that it is only marginally stable. This area is planned for open space, however, so slope stability in this area is not a concern. Hydrologic Issues The Parkside Estates site is, geomorphologically, a flood plain. However, construction of the levees associated with the East Garden Grove Wintersburg Flood Control Channel have functionally isolated the river channel from the flood plain. Moreover, the Parkside Estates site lies at elevations of 1 to 2 feet below sea level. Areas of the surrounding neighborhoods lie at elevations of as low as 5 feet below sea level. Low berms in the Bolsa Chica lowlands, in addition to the East Garden Grove Wintersburg Flood Control Channel levees, protect these neighborhoods from tidal flooding. Storm water must be collected through a series of storm drains lying well below sea level, and pumped up into the East Garden Grove Wintersburg Flood Control Channel through a forebay at the Slater Pump station, which is on the south side of the flood control channel adjacent to the Parkside Estates parcel. The capacity of the existing flood control channel is insufficient to carry the 100-year flood event. References (1) and (2) conclude that the channel will carry only about 4,200 cfs and will overflow in a 100 year event. Because the south levee is mostly lower than the north, more water would overflow to the south, and into the Bolsa Chica wetlands, than to the north. Nevertheless a total of about 52 acre feet would overtop the north levee in a 100-year flood event. In fact, overtopping of the levees will likely result in their complete failure, with a resultant loss of capacity of the flood control channel and inundation by ocean waters.



Commission

Future development in this challenging environment must be undertaken to assure safety given inevitable flooding both from surface runoff and tidal surges and/or tsunamis.


Background The January 1997 Flood Insurance Rate Map (FIRM), issued by the Federal Emergency Management Agency (FEMA) designated the project site as an A99 zone. This designation applies to parts of the 100-year flood plain that are protected by a Federal flood protection system (in this case, The East Garden Grove Wintersburg Flood Control Channel). Because the A99 zone was considered an ”interim“ zone pending completion of the Santa Ana River project, the local authority (the City of Huntington Beach) had the discretion to dictate minimum pad elevations for the project. At the time the draft EIR was prepared, the City of Huntington Beach required minimum pad elevations for the project site to be 1.00 foot (NAVD 88 datum). Subsequent to completion of the Santa Ana River flood control improvements in 1999, FEMA required the Orange County Flood Control District to conduct a new analysis of the watershed. The Orange County Flood Control District commissioned WEST Consultants to do a detailed study. Instead, WEST, at the direction of the County, provided an “approximate” watershed analysis. Subsequently, in June 2000, new base flood elevation contours were “informally” produced by the County of Orange from the WEST study. These new informal, non-published or “unofficial” base flood elevation contours were made available to the City of Huntington Beach on an information basis to establish minimum pad elevations for new developments within the watershed study area. The City's interpretation of the base flood contours required pad elevations for the Parkside Estates site that ranged between 10.9 feet and 11.4 feet (NAVD 88). FEMA then issued a Letter of Map Revision (LOMR) which became effective June 14, 2000 along with a revised Flood Insurance Rate Map based on the City’s interpretation of the WEST study. However, Shea Homes objected to the use of an “approximate” study to establish Base Flood Elevations. They commissioned Exponent to conduct a “new focused detailed flood insurance study” to determine the Base Flood Elevation for the Parkside Estates site (summarized in reference 9). The Exponent analysis yielded a Base Flood Elevation of 4.5 feet (NAVD 88). The minimum pad elevations are required by the City to be one foot above the minimum Base Flood Elevation, or 5.5 feet (NAVD 88). In February 2001, Shea Homes submitted a request for a Conditional Letter of Map Revision (CLOMR) application to FEMA for approval of the lower elevations. FEMA granted the CLMOR on 6 June 2002.

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Application Number: HNB-MAJ-1-06 C

Mark Bixby and others have objected to this CLOMR on the basis of: 1) The East Garden Grove Wintersburg Flood Control Channel does not have the capacity to carry the 100-year flood, and the County would require throttling back of pumps that would be draining Parkside; accordingly Base Flood Elevations calculated assuming those pumps running at full capacity are in error, and 2) documented siltation and vegetation growing in the East Garden Grove Wintersburg Flood Control Channel decreases its capacity relative to the assumptions in the hydrological studies.

alifornia Coastal Commission

I have pursued these issues with Neil Jordan of Exponent and Steve Barnhart of Hunsakers and Associates, together with representatives of the City of Huntington Beach. It has been demonstrated to my satisfaction (references 9 and 16) that the detailed flood insurance study conducted by Exponent made use of many diverse hydrologic models that included complete


failure of the East Garden Grove Wintersburg Flood Control Channel levees, failure of the pumps, and variations in timing of the failures of both levees and pumps. The Base Flood Elevation determined in this study is the worst case ponding elevations of all of these models. Accordingly, I feel that the 100-year Base Flood Elevations for the Parkside Estate site determined in reference (9) are consistent with FEMA policies and assure the safety of the site during a 100-year flood event. As for the siltation and vegetation in the East Garden Grove Wintersburg Flood Control Channel that Mark Bixby documents, I concur that these materials lower the carrying capacity of these channels. Although these materials would lower the capacity of the channels to carry small or moderate-level flows, in the high flows (~4000 cubic feet per second) corresponding to bank-full discharge, these materials would be flushed from the channel. Elevating the site above Base Flood Elevation In order to concur with City and FEMA requirements, final building pad elevations must be one foot above the Base Flood Elevation. The proposed grading plan has final pad elevations ranging from 5.5 feet to 11.4 feet above sea level. Given that the existing site lies between 1 and 2 feet below sea level, these elevations are achieved by adding approximately 260,000 cubic yards of fill to the site. Actually, as described above, overexcavation to depths as great as 17 feet below sea level is necessary to mitigate the liquefaction hazard. Accordingly, development of the site requires approximately 400,000 cubic yards of cut and 660,000 cubic yards of fill, representing significant landform alteration. In general, use of fill to elevate a building site above expected flood levels is poor planning practice. The volume of fill added to the site represents the volume of floodwater that will be displaced into neighboring areas. The Parkside Estates site, at 1 to 2 feet below sea level, is at a higher elevation than the lowest portions of the surrounding neighborhoods, where streets are at elevations as low as 5 feet below sea level. Building pads in these neighborhoods generally are higher than streets, at elevations of from one foot below sea level to 4 feet above sea level. If no mitigation were undertaken, flooding of these neighborhoods would be exacerbated by the addition of fill at the Parkside Estates site. Tidal Flooding

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Commission

The area to the southwest of the Parkside Estates site, north of the East Garden Grove Wintersburg Flood Control Channel and south of the Bolsa Chica mesa, is a lowland that is susceptible to tidal flooding. This susceptibility will be increased with the construction of a future tidal inlet as part of the Bolsa Chica wetlands restoration. In fact, according to reference (9), some 170 acres of the watershed, much of which is developed, would be threatened by tidal flooding by the restoration. This area would be protected only by low berms supporting oil field roads at elevations of less than 4 feet above sea level.


Improvements to area drainage systems Shea Homes has proposed to make several improvements to the area drainage system. These include: 1) improving the capacity and stability of the East Garden Grove Wintersburg Flood Control Channel, probably by widening it and by installing a sheet pile wall for levee support; 2) Making changes to storm drains under Kenilworth Drive and Graham Streets, improving their capacity; 3) Upgrading the Slater Pump Station by installing two more pumps, and 4) constructing a “Vegetated Flood Protection Feature” (essentially a vegetated berm) at an elevation of 11 feet above sea level between the bluff and the north levee of the East Garden Grove Wintersburg Flood Control Channel to prevent tidal flooding of the Parkside Estates site as well as 170 acres of the surrounding neighborhoods. Together, these improvements more than mitigate for the lost flood water storage caused by the addition of fill to the Parkside Estates site. According to references (9) (13) and (16), these improvements would remove 7000 homes from the functional flood plain, and would reduce flood elevations throughout the watershed. Still, overtopping of the East Garden Grove Wintersburg Flood Control Channel levees upstream of the Parkside Estates would occur in a 100-year event if these levees are not improved in a similar manner to that being done adjacent to Parkside Estates. These improvements are the responsibility of the County of Orange, and FEMA has directed the County to make these improvements. Even without these improvements, however, the proposed improvements at the Parkside Estates site would ensure that the Parkside Estates building pads would lie above the 100-year Base Flood Elevation, as required by FEMA. Tsunamis The Huntington Beach lowlands are quite vulnerable to a major tsunami. A tsunami that overtopped the low berms associated with the Pacific Coast Highway and the oil field roads in the Bolsa Chica wetlands could inundate a large area of the lowlands, much of which lies below sea level. The proposed “vegetated flood protection feature” and the improvements to the north levee of the East Garden Grove Wintersburg Flood Control Channel, together with the increased pad elevation, will lower the vulnerability of the Parkside Estates site. Although the placement of fill on the site would displace flood waters into the surrounding neighborhood during a major tsunami, the “vegetated flood protection feature” does lower the susceptibility of this area to smaller tsunamis. Conclusions

EXPa

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Commission

In summary, the Parkside Estates is not suitable for residential development without fairly extensive mitigation measures, especially for the liquefaction and flood hazards. Shea Homes’ planned method of remediation involves extensive landform alteration in the form of adding fill to raise the site above Base Flood Elevation. Although this is not a generally recommended method of mitigating a flooding hazard due to the effects it can have on adjacent areas, the planned drainage system improvements more than mitigate for these effects. The necessary excavations and dewatering operations have the capacity to induce subsidence or other instability in adjacent sites, but these effects will be mitigated by doing the excavation in stages and by


careful monitoring. The site will experience strong ground shaking during a major earthquake. Early reports that an active fault crosses the site cannot, however, be supported by the data currently available. I hope that this review is helpful. Please contact me if you have additional questions Sincerely,

Mark Johnsson, Ph.D., CEG, CHG Staff Geologist



Commission


STATE OF CALIFORNIA—THE RESOURCES AGENCY ARNOLD SCHWARZENEGGER, GOVERNOR

CALIFORNIA COASTAL COMMISSION 45 FREMONT, SUITE 2000 SAN FRANCISCO, CA 94105- 2219 VOICE AND TDD (415) 904- 5200 FAX ( 415) 904- 5400

M E M O R A N D U M FROM: John Dixon, Ph.D. Ecologist / Wetland Coordinator

TO: Meg Vaughn

SUBJECT: Wetlands at Shea Homes Parkside

DATE: July 27, 2006

Documents reviewed: Barnes, J.R. (City of Huntington Beach). January 8, 1998. Letter to T. Dickerson

(CDFG) re: “Request for comment on Shea Homes property wetlands status.” Bilhorn, T.W. (Earth Science Consultant). September 1986a. Seasonal variations in

the extent of ponded surface water in the Bolsa Chica lowland, Orange County, California. A report to Signal Bolsa Corporation.

Bilhorn, T.W. 1986b. Shallow ground water system of the Bolsa Chica lowland, Orange

County, California. A report to Signal Bolsa Corporation. [Not held; cited in Sanders (1987) and EPA (1989).]

Bilhorn, T.W. June 1987. Agricultural area delineation, Bolsa Chica, Orange County,

California. A report to Signal Bolsa Corporation. Bilhorn, T.W. February 25, 1995. Hydrology and cartography, Bolsa Chica Area,

California. Supportive information to a Section 404 delineation. A report to D.R. Sanders & Associates.

Bixby, M. 2005. Ponding at Shea Parkside. A website containing ground-level and

aerial photographs of the agricultural area and the former county parcel owned by Shea Homes (http://www.bixby.org/parkside/multimedia/ponding/index.html).

Bomkamp, T. (Glenn Lukos Associates). (May 7) 2005a. Memorandum to J. Dixon

(CCC) re: “Areas requiring clarification within May 4, 2005, technical memorandum regarding application of atypical situation methodology for Parkside Estates.

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Bomkamp, T. (June 8) 2005b. Letter to J. Dixon (CCC) re: “Analysis of ‘Atypical Situation’ methodology and hydrology on the Parkside Estates site, based on historic and existing conditions.”

. Dixon memorandum to M. Vaughn dated 07/27/06 re wetlands on Shea Homes Property Page 2 of 99

Bomkamp, T. (Glenn Lukos Associates). (February 22) 2006a. Memorandum to J. Dixon and M. Vaughn (CCC) re: “Summary of Alpha, alpha-dipyridyl Testing for WP Area, AP Area and County Parcel at Parkside Estates.”

Bomkamp, T. (Glenn Lukos Associates). (March 30) 2006b. Memorandum to J. Dixon

and M. Vaughn (CCC) re: “Alpha, alpha-dipyridyl Testing for AP Area and County Parcel between February 24 and March 28, 2006 at Parkside Estates.”

Bomkamp, T. (Glenn Lukos Associates). (June 5) 2006c. Memorandum to J. Dixon

(CCC) re: “Expanded Discussion of Alpha, alpha-dipyridyl Testing Procedures.” Bomkamp, T. (Glenn Lukos Associates). (June 26) 2006d. Memorandum to J. Dixon

(CCC) re: “Additional information for Parkside prepared in response to [J. Dixon’s] June 9, 2006 email.”

Bomkamp, T. (Glenn Lukos Associates) and A. Homrighausen (LSA). February 16,

2006. Memorandum to J. Dixon (CCC) re: “Alpha, alpha-dipyridyl Testing Methodology.”

Bomkamp, T. (Glenn Lukos Assoc.), N. Jordan (Exponent), and R. Ray (Exponent).

May 15, 2006. A technical memorandum to J. Dixon and M. Vaughn (CCC) re: “Additional data regarding differences between County parcel and “AP” and “WP” areas, Parkside Estates.”

Bomkamp, T. and S. Young (Glenn Lukos Associates). March 23, 2005. Memorandum

to M. Vaughn and J. Dixon (CCC) re: “Explanation of apparent contradiction between photographic evidence provided by Mr. Mark Bixby relative to ponded areas on the Shea Homes Parkside Estates site and the January 6, 2004 wetland determination (WD) prepared by Glenn Lukos Associates.”

Bomkamp, T., S. Young, and J. Harrison (LSA). May 4, 2005. Memorandum to J.

Dixon and M. Vaughn (CCC) re: “Application of ‘Atypical Situation’ methodology to City Parcel, Parkside Estates project site, Orange County, California.”

Castles, J.B. (Pacific Soils Engineering). March 29, 2006. Letter report to R. Metzler

(Shea Homes) re: “Update of Groundwater Monitoring, Parkside Estates, Tract 15377, City of Huntington Beach, California.”

CDFG. c. 1981. Figure 1.7. to an unknown report: CDFG Wetlands Determination

Map. Graphic based on compilation of four individual maps drawn on 10/7/81. EPA, Region IX. February 1989. A determination of the geographical extent of waters

of the United States at Bolsa Chica, Orange County, California.

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Feldmeth, C.R. (Ecological Consultant). August 5, 1991. Letter to L. Brose (Koll Co.) re: current characterization of the MWD property.


Fontaine, J. (Trestles Environmental Corp.). June 29, 2005. Letter report to M. *Stirdivant (Bolsa Chica Land Trust) re “Assessment of ‘Delineation of Wetland Subject to U.S. Army Corps of Engineers and California Coastal Commission Regulatory Authority” Prepared by LSA Assocaites, Inc. May 21, 2002.”

Fontaine, J. (Trestles Environmental Corp.). (June 29) 2005a. Letter report to M.

Stirdivant (Bolsa Chica Land Trust) re “Technical analysis regarding the jurisdictional delineation and other technical memorandum (sic) prepared for the 45-acre ‘city portion’ of the Shea Homes property in Huntington Beach, California.”

Fontaine, J. (Trestles Environmental Corp.). (June 29) 2005b. Letter report to M.

Stirdivant (Bolsa Chica Land Trust) re “Assessment of ‘Delineation of wetland subject to U.S. Army Corps of Engineers and California Coastal Commission regulatory Authority’ prepared by LSA Associates, Inc. May 21, 2002.”

Fontaine, J. (Trestles Environmental Corp.). (October 8) 2005c. Letter report to M.

Stirdivant (Bolsa Chica Land Trust) re “Review of 1987 Huffman report and letter of conclusions for wetlands on the Shea property in Huntington Beach, California.”

Fontaine, J. (Trestles Environmental Corp.). June 12, 2006. Letter report to M.

Stirdivant (Bolsa Chica Land Trust) re “Review of GLA 2006 hydric soil analysis and other comments of January 2006 J.Dixon letter regarding the Shea Homes property in Huntington Beach, California.”

Frank Havore & Associates. December 10, 1997. Biological resources assessment,

Shea Homes property, project #6N153.01, Huntington Beach, California. Gill, J. (ACOE). May 20, 1992. Letter to Beveridge & Diamond, P.C. declaring the

MWD property to be “prior converted cropland” and not jurisdicational under Section 404 of the Clean Water Act.

Glenn Lukos Associates. May, 2006. Summary of technical papers relative to possible

wetland status of portions of the Parkside Estates site known as “County Parcel” and the “AP” and “WP” areas. A report submitted to the CCC.

Glenn Lukos Associates. June 3, 2006. Parkside Estates Summary of Alpha-Alpha

Dipyridyl Testing Data January-May 2006. A tabular data sheet submitted alone. Harrison, J. (LSA). December 8, 2000. Letter report to R.C. Metzler (Shea Homes) re:

“Habitat analysis, Parkside Estates Tentative Tract No. 15419 (County Parcel), Orange County, California.”

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Harrison, J. and A. Homrighausen (LSA). January 2, 2003. Letter report to R. Metzler (Shea Homes) re “Disturbance by agricultural tenant on She Homes property in the County of Orange.”


Hewitt, R.S. (Natural Resources Conservation Service). November 20, 1998. Letter to J. Barnes (City of Huntington Beach) concurring with the Corps’s designation of the wetlands on the agricultural parcel of the Shea property as “prior converted cropland.”

Homrighausen, A. (LSA). March 23, 2005. Letter report to M.Vaughn (CCC) re:

“Technical response to February 28, 2005, California Coastal Commission letter, Coastal Development Permit application No. 5-03-029 (Shea Homes)”

Homrighausen, A. (LSA). September 15, 2005. Letter report to J. Dixon (CCC) re:

“Parkside Estates Project: HNB LCPA No. 1-05 and CDP Application No. 5-05-256, Technical Response to Staff Analysis Presented at Meeting of June 30, 2005.”

Huffman, R.T. 1987. A report on the presence of wetland and other aquatic habitats

within the Bolsa Chica lowlands. A report to the USEPA, Region IX, San Francisco, California.

Hunsaker & Associates. May 20, 2004. Site topography comparison: 1996 to 2003.

Appendix D to an unspecified report. Jordan, N.M. (Exponent). (February 22) 2006a. Frequency analysis of precipitation

and ponding at Parkside Estates. A report prepared for Shea Homes. Jordan, N.M. (Exponent). (February 22) 2006b. Correlational and frequency analysis of

groundwater at Parkside Estates. A report prepared for Shea Homes. Josselyn, M. (June 24) 2006a. Biogeochemical processes and their significance for

making a Coastal Commission wetland determination at Parkside. A report submitted to the CCC.

Josselyn, M. (June 29) 2006b. Memorandum to J. Dixon (CCC) re: “Response to

question concerning alpha, alpha, dipyridyl.” Kegarice, L.M. (Tom Dodson & Associates). December 17, 1997. Letter report to J.

Morgan (EDAW Inc.) re: “Verification/update of wetland determinations for TT#15377”

LSA. May 21, 2002. Delineation of wetlands subject to U.S. Army Corps of Engineers

and California Coastal Commission regulatory authority. Parkside Estates Tentative Tract No. 15419, County of Orange, California. A report to Shea Homes.



California Coastal

Commission

LSA. June, 2005. Excel database (20050719_58-05 PRECIP ONLY.XLS) containing precipitation data for Los Alamitos (Station 170; 1958-2003) and Costa Mesa (Station 219; 2003-2005).


Pacific Soils Engineering, Inc. February 2, 1998. Preliminary geotechnical investigation, proposed residential development Tentative Tract 15377, City of Huntington Beach, California and Tentative Tract 15419, County of Orange, California. A report to Shea Homes Southern California, Inc. (Not held; citation from Young and Bombkamp 2004)

Rempel, R.D. (CDFG). March 16, 1998. Letter to J.R. Barnes (City of Huntington

Beach) concurring with the Tom Dodson report (Kegarice 1997) that found no wetlands on the Shea site.

Sanders, D.R. June 24, 1987. Determination of waters of the United States, including

wetlands, at Bolsa Chica, California. A report to Beveridge & Diamond, P.C. Sanders, D.R. October 10, 1991. Letter to R. Sater (Beveridge & Diamond, P.C.) re:

“Investigation of MWD portion of Bolsa Chica with respect to prior-converted cropland versus farmed wetland status.”

Sanders, D.R. (Wetland Consultant). December 1994. Identification and delineation of

“Waters of the United States” under Clean Water Act Section 404, Bolsa Chica, Orange County, California. A report to Koll Real Estate Group.

Sanders, D.R., T.W. Bilhorn, and C.R. Feldmeth. April 27, 1989. Technical comments

on the Environmental Protection Agency jurisdictional determination at Bolsa Chica. A report to Beveridge & Diamond, P.C.

Schaefer, C. (TAIC). March 21, 2005. Letter report to Bolsa Chica Land Trust re:

“Review of ‘Wetland determination for the Parkside Estates site in the City of Huntington Beach, Orange County, California’ by Glenn Lukos Associates and ‘Alternatives to Shea Parkside at Bolsa Chica’ website by Mark Bixby to clarify wetlands determinations for the Shea Parkside property in Huntington Beach, California”

van de Hoek, R.R. (Biologist). October 21, 2002. Report for the Bolsa Chica north-east

wetland “Wintersburg Wetland” Vandersloot, J.D. October 30, 2002. Letter to R. Rempel (CDFG) requesting the

Department to re-evaluate the Shea property for wetlands.

U.S. Army Corps of Engineers. September 26, 1990. Regulatory Guidance Letter 90-07, Subject: Clarification of the phrase “normal circumstances” as it pertains to cropped welands.


Wright, W.W. (Ecologist). March 12, 2005. An overview of biological resources, Shea Homes Property at Bolsa Chica, 17301 Graham Street, Huntington Beach, CA. A report to the Bolsa Chica Land Trust.


California Coastal

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Young, S. and T. Bomkamp. January 6, 2004. Letter report to R. Metzler (Shea Homes) re: “Wetland determination for the Parkside Estates site in the City of Huntington Beach, Orange County, California”


Introduction Any useful wetland analysis of the Shea Homes property (Figure 1) in Huntington Beach must attempt to answer the question, “Are any portions of the property wet enough long enough and frequently enough to promote the formation of hydric soils or to support the growth of a preponderance1 of wetland plant species?” If the answer is “yes,” then such areas meet the definition2 of “wetland” under the Coastal Act and the Commission’s Regulations. Unfortunately, wetland delineation at the Shea Homes site is difficult because (1) the site has been farmed for many years and both native and exotic non-crop plants are routinely removed; therefore, the absence of wetland vegetation is not informative, (2) although historically saltmarsh with hydric soils, the site is now dependent on rainfall for hydrology and the soil is repeatedly disturbed by plowing; therefore, neither the presence nor the absence of the usual physical indicators of wetland soils is easily interpretable, and (3) there are no long-term records of inundation or saturation. There is no entirely satisfactory solution to these problems. However, the hydrological character of the site can be inferred from photographs and rainfall records and the general type of vegetation (wetland or upland) that would develop in the absence of farming can be inferred from the character of a nearby site that is topographically and hydrologically similar, but generally not farmed. Historical Background The Bolsa Chica lowland was created by the down-cutting of the Santa Ana River prior to its change in course in the late 1800s. The wetlands once encompassed over 2000 acres, including the current Shea Homes property. Remnants of sinuous channels from the historical saltmarsh are still present in the portions of the lowland that are presently undergoing restoration and the ghosts of such channels can be seen on aerial photographs of the Shea Homes property as dark outlines that probably reflect residual differences in soil texture and moisture retention. As late as 1873, much of the area was still a tidal lagoon. However, significant anthropogenic impacts began toward the end of the 19th century. Since that time, the ocean inlet was closed, much of the wetlands was diked and filled for oil field construction, the East Garden Grove-Wintersburg Flood Control Channel was constructed, and residential neighborhoods replaced portions of the historical wetlands that are adjacent to the Shea Homes property. The Shea Homes property is the most constrained of the still-extant portions of the historical Bolsa Chica wetlands. It is bounded on the north by residential development, the final portion of which was completed around 1985. It is bounded on the east by Graham Street, on the south by the flood control channel, and on the west by the Bolsa Chica mesa and an elevated area that prevents runoff from most of the site



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1 “Preponderance” is defined as more than 50 % of the dominant species present (1987 Army Corps of Engineers Wetland Delineation Manual). 2 For an area to meet the definition of “wetland” recognized by the Army Corps of Engineers and the U.S. Environmental Protection Agency, there must be field evidence of a preponderance of wetland plants, of hydric soils, and of wetland hydrology. The California Department of Fish and Game and the California Coastal Commission employ the same field methods as do the federal agencies, but require evidence of only one of the three wetland parameters for an area to be identified as a “wetland.”


from draining to wetlands farther to the west. The topography of the site has been altered in partially documented ways by agricultural operations. The area has long been cutoff from tidal waters. Today, the only source of water is direct rainfall and runoff from the higher to the lower portions of the site. Wetland Delineations Extensive wetland delineation work was conducted at Bolsa Chica during the 1980s3 by both the U. S. Environmental Protection Agency (EPA) and Signal Bolsa Corporation. In 1987, Dr. Terry Huffman, working for the EPA, identified 1,270 acres of wetlands and “other waters of the United States” within his approximately 1,400-ac study area, which did not include the Shea Homes property (Huffman 1987, Figure 3). Although not part of his study area, Huffman (1987, p.47 & Figure 15) noted that he found wetlands on the current Shea Homes property during an examination of upslope drainage patterns and refers to the area as “seasonally flooded agricultural lands.” However, he did not depict the wetlands on a map. Also in 1987, Dr. Dana Sanders, working for Signal Bolsa Corporation, identified 826 acres of wetlands and “other waters of the United States within a study area of about 1,654 acres, which did include the current Shea Homes property where he mapped about 8 acres of wetlands, based largely on Bilhorn’s (1987) wetland study (Figure 2). After reviewing all the available evidence, EPA identified 927 acres of wetlands and other waters of the United States, including about 8 acres on the current Shea Homes property as identified by Bilhorn (1987) and Sanders (1987). Bilhorn (1987) based his conclusions on (1) a field examination (including test pits and borings) on April 15, 1987, (2) nearby rainfall records, (3) a 1980 topographic map, (4) approximately monthly low altitude, oblique aerial photographs covering the period 1981 - 1987, (5) historical aerial photos dating to 1927, and (6) the documented history of land alterations affecting the area. His wetland map was based on the wetted area shown on a 1982 aerial photograph (selected to represent a normal rainfall year) and the 1980 elevations. Referring to the agricultural portion of what is now the Shea Homes Property, Sanders (1987) found that [emphasis added]:

“Surface elevations of much of the subunit are below sea level. Based on application of the multiparameter approach, the entire subunit (43.8 acres) is presently uplands. This is due to the absence of wetlands hydrology in most of the subunit and hydrophytic vegetation throughout. However, it was determined that a portion of the subunit would probably be sufficiently wet to support



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3 During this period, the Army Corps of Engineers was developing the methods that became codified in the 1987 Corps of Engineers Wetlands Delineation Manual and three of the four principal authors of that manual actually did field work at Bolsa Chica as paid consultants for either the EPA or for the major property owner, Signal Bolsa Corporation. At that time, the parcel now owned by Shea Homes was the property of the Metropolitan Water District of Southern California and the City parcel (Figure 1) had been farmed since the mid-1930s. The EPA, Region IX contracted with Dr. Terry Huffman, the co-author of the 1987 Manual who had developed the three-parameter approach to wetland delineation, to conduct a delineation of wetlands and other waters of the United States at Bolsa Chica. Other members of the EPA Technical advisory team included W. Blake Parker, who had developed hydric soil concepts while on loan to the Army Corps of Engineers from the Soil Conservation Service and who also co-authored the 1987 Manual, and William Sipple, the author of the 1988 EPA Wetland Identification and Delineation Manual. Dr. Dana Sanders, another co-author and the Technical Editor of the 1987 Corps Manual, was hired by Signal Bolsa Corporation to conduct an independent delineation.


hydrophytic vegetation if the farming activities were to cease. Soils in a major portion of the root zone during years of near-normal rainfall would not be saturated by rise of water from the water table due to capillary action. The only source of sufficient water to saturate the soils in a major portion of the root zone in this subunit is from surface water runoff following significant rainfall events. Only depressional areas would be saturated sufficiently to support the growth of hydrophytic vegetation.”

EPA (1989) concluded that, “…portions of the agricultural fields would be inundated or saturated at a frequency and duration sufficient to support a prevalence of hydrophytic vegetation in the absence of 404(f)-exempted farming activities (see Bilhorn 1987) and are, therefore, wetlands subject to Section 404 regulation.” These various conclusions were all based on the assumption that there was no wetland hydrology resulting from a seasonally high water table, but rather that direct rainfall and local runoff into depressions was sufficient to provide wetland conditions. There have been no significant alterations to the overall hydrology at the site since 1987. In the 1988 National Food Security Act Manual, the Soil Conservation Service defined “prior converted croplands” as wetlands that, prior to December 23, 1985, were both cropped and manipulated to remove excess water to the extent that they no longer exhibit important wetland values. Specifically, such areas are inundated for less than 15 consecutive days during the growing season (all year in coastal California). In a Regulatory Guidance Letter (RGL 90-07) dated September 26, 1990, the Army Corps of Engineers declared that if an area meets the definition of “prior converted croplands,” the alterations are generally permanent and constitute “normal circumstances,” which makes the altered conditions relevant to the areas’ wetland status under federal law, as the Army Corps’ definition of wetlands (see 33 C.F.R. § 328.3(b)) relies on their function under “normal circumstances.” Therefore, because such agricultural areas lack a “prevalence of hydrophytic vegetation” as a result of the farming activities, they would not be subject to regulation under Section 404 of the Clean Water Act. The following year, at the request of counsel, Dr. Sanders re-assessed the current Shea Homes property and concluded that it was “prior converted cropland” and not regulated under the Clean Water Act. Dr. Sanders made the following false assertions4 (compare to bold text in above citation) in his 1991 letter to Beveridge and Diamond [emphasis added]:

“According to my 1987 wetland delineation of the MWD property, the source of wetlands hydrology for the 8.1 acres qualifying as wetlands is a water table that rises to nearer than 18 inches of the soil surface during years of normal rainfall (Sanders, 1987). The area was not delineated as wetlands on the basis of indicators that the area is periodically inundated. In fact, the area would not have been considered as wetlands except for the high water table expected during years of normal rainfall (Bilhorn, 1987). All available data



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4 Section 5c of the Corps’ RGL 90-07 states that, “The definition of ‘normal circumstances’…is based upon the premise that…the basic soil and hydrological characteristics remain to the extent that hydrophytic vegetation would return if the cropping ceased. This assumption is valid for ‘farmed wetlands’ and as such these areas are subject to regulation under section 404.” If Dr. Sanders had accurately represented his 1987 findings, wherein he said “it was determined that a portion of the subunit would probably be sufficiently wet to support hydrophytic vegetation if the farming activities were to cease,” the area might not have been considered “prior converted cropland.”


indicate that the area is not inundated for long periods following rainfall events.” 5

The conclusion that the wetland hydrology resulted from groundwater rather than surface inundation brought the area within the definition of “prior converted cropland” and rendered it outside of Section 404 regulation.] In fact, no quantitative data regarding inundation of the MWD parcel was presented in any of the documents. The nearest thing to data was a statement by Sanders (1991) that during 1987-1988 he saw no indications of inundation and a statement by Bilhorn (1987) that, “Analysis of the monthly aerial photographs confirms that the surface layer remains dry from groundwater during the water table seasonal high. The appearance and disappearance of moist soils in this area are brief (days) and correlate to rainfall events and not water table fluctuations which are of shorter duration.” On the other hand, in the same document Bilhorn states that the area he delineated, “…was indicated by aerial photographs to receive surface water repeatedly from adjacent areas during the winter rainy season.” Although these observations are somewhat ambiguous, it was the professional judgment of both the Signal Bolsa Corporation scientists and the EPA scientists that portions of the current Shea Homes property were inundated for a frequency and duration that would promote the growth of hydrophytes in the absence of farming. Homrighausen (2005) dismisses Sanders’s contradictory observations as merely “background information” and suggests that the finding of “prior converted cropland” was only based on Sanders’s (1991) conclusions that the previously identified wetlands would not pond water for more than 14 days because of a high evapotranspiration rate, low average rainfall, a small watershed, and no runoff from surrounding areas (none of which had changed since 1987). Even if one accepts this generous interpretation, one must still conclude that although the delineated area may not be sufficiently wet to be considered jurisdictional by the Army Corps of Engineers, it was, nevertheless, judged wet enough long enough to support a prevalence of hydrophytes in the absence of farming (Sanders 1987); therefore, as Sanders (1991) later put it, “technically qualifying as wetlands”. Therefore, in 1991 the area met the definition of “wetlands” under the Coastal Act and the Commission’s Regulations. Apparently based on information from MWD and Dr. Sanders, the Corps of Engineers concluded in 1992 that the MWD property was not jurisdictional because it “…meets the criteria for prior converted cropland as presented in RGL 90-07, and the lack of information to the contrary….”6 In 1998, the Natural Resources Conservation Service concurred with the Corps’s conclusion based on a review of the record. Neither of these jurisdictional determinations were based on new data.



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5 Bilhorn (1987) actually wrote that: “Lithologic examinations show the surface to a 14- to 20-inch depth to be a silty clay.” and “…the water table would lie 8 to 13 inches below the silty clay material and thus could not saturate this material by capillary processes.” The affect of Sanders’s later (1991) claim to the contrary - that the wetland was supported only by shallow groundwater and was not inundated - was to bring the area within the definition of “prior converted cropland” and outside of Section 404 regulation. 6 Basing an affirmative conclusion on a “lack of information to the contrary” is, at the least, a questionable procedure.


Sanders’s (1991) misrepresentation of his and Bilhorn’s 1987 reports has been perpetuated and, indeed, embellished by later commentators, further muddying the record. Kegarice (1997), after accurately quoting from Sanders (1987), then presented assertions from Sanders’s contradictory 1991 letter without noting the obvious discrepancies, and gratuitously added the following, which was not in Sanders’s letter: “Sanders later found out the hydrologic data observing a saturated condition and high ground water was taken in 1983. 1983 recorded the second highest rainfall ever, and did not represent the average year. Therefore, in 1991 Sanders revisited the site and modified his report based upon this additional information.” In fact, there was no “additional information.” Bilhorn’s (1987) report was based on [emphasis added] a “…comparison of water table elevation differences throughout the Bolsa Chica Lowland piezometer network between the current 1986-1987 season and the normal rainfall year of 1981-1982….”7 Like Kegarice, Young and Bomkamp (2004) incorrectly assert that, “In his 1991 evaluation, Dr. Sanders noted that his earlier finding of wetland hydrology in the 8.3-acre area was based entirely on the 1983 groundwater data collected by Bilhorn.” Young and Bomkamp (2004) also grossly mischaracterize Bilhorn’s (1987) report: “Bilhorn recorded groundwater at a sufficiently shallow depth during the spring of 1983 to cause saturation to the surface, assuming strong capillary action.” Although these egregious errors raise doubts about the general accuracy of the documents that contain them, I consider the technical issue moot because none of the original reports claimed or presented data to the effect that there were wetlands in the agricultural area of the current Shea Homes property whose hydrology was based on a seasonally shallow water table. Ground water isopleths become deeper inland along a steep gradient (Bilhorn 1986, as cited in EPA 1989; Bilhorn 1995). Ground water in the lower portions of the agricultural area probably varies seasonally from about –3.0 to –8.0 feet below the surface during most years. This was apparently verified by Pacific Soils (1998) in a study that was characterized by Kegarice (1997) as finding groundwater from –3 to –9.5 feet during the winter, and by Young and Bomkamp (2004) as showing that groundwater occurs at about –6.0 feet in the agricultural area. I think it is clear that any wetlands that may be present in the agricultural portion of the Shea Homes site result primarily from surface hydrology, and this was the conclusion of Bilhorn (1987), Sanders (1987) and EPA (1989) nearly twenty years ago. In 1991, Feldmeth surveyed the property for the Koll Company, apparently because of a report of a ponded area with cattails. The latter turned out to be the result of water from an irrigation pipe. However, Feldmeth also noted that a 3.3-acre area adjacent to the East Wintersburg-Garden Grove Flood Control Channel (now designated WP) was dominated by the facultative (FAC8) wetland plant Bassia hyssopifolia, which is currently common on the County parcel9.



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7 Sanders’s only reference to 1983 was in a assertion that there was no evidence that the area was periodically inundated, except “…during the 1983 rainfall year, for which the return frequency exceeded 100 years.” However, Bilhorn (1987) had observed that the delineated area was, “…indicated by aerial photographs to receive surface water repeatedly from adjacent areas during the winter rainy season.” 8Wetland plant species are categorized according to the frequency with which they are thought to occur in wetlands: “Obligate Wetland (OBL) – > 99% of occurrences in wetlands under natural conditions; Facultative Wetland (FACW) – 67-99% of occurrences in wetlands; Facultative (FAC) – 34-66% of occurrences in wetlands; Facultative Upland – 1-33% of occurrences in wetlands; Obligate Upland (UPL) - > 99% of occurrences in uplands under


Apparently, the next wetland assessment that included the Shea Homes property was that which was conducted by Tom Dodson and Associates (Kegarice, 1997). This assessment was based largely on a literature review and a site visit on November 20, 1997 to verify the earlier reports. Soil pits were dug but no data sheets were included with the report and no quantitative samples of vegetation were reported. It was stated that, “The soils on the site are not frequently flooded for long durations.” However, no evidence was provided for that assertion. It was also asserted that the land did not support a predominance of hydrophytes based on the qualitative observation that the dominant cover was provided by non-wetland species. One would not expect a predominance of hydrophytes, even in wetlands, shortly after agricultural disturbance (see below). In addition to the errors noted above, Kegarice asserts that both Bilhorn and Sanders concluded that the site was not wet enough to support hydrophytes. Neither of them made that claim. In fact, Sanders (1987) found the opposite. Kegarice was accompanied on the site visit by Frank Hovore. Biologists from Hovore and Associates visited the site in November and December 1996 and January and June 1997 in addition to the November 1997 visit with Kegarice. Hovore (1997) states that on several survey dates the surface soils were saturated by recent rains and there was standing water in depressions. The report also includes this apparent non sequitur, “There are no seasonal pools or channels on the site, but aerial photos frequently show a shallow accumulation of surface water in the northwestern corner of the City property, approximately where the 8.3 acre area was delineated.” I speculate that Mr. Hovore may have meant that the observed inundation was relatively brief. However, he does not specify how long an area must be inundated for it to qualify as a “seasonal pool” by his reckoning. The Hovore report provides additional useful detail concerning the vegetation. The agricultural area had been left fallow for about 5 months prior to the November 1997 site assessment. Most portions of the fallow fields were dominated by a relatively homogeneous cover of Bermuda grass (FAC) and cheeseweed (Upland) with scattered patches of both upland and wetland indicator species. Less-disturbed areas were characterized by alkali heath (Frankenia salina, FACW), Salt bush (Atriplex triangularis; not listed as an indicator but a characteristic salt marsh species in California), sand spurrey (Spergularia marina, OBL), alkali mallow (Malvella leprosa, FAC*), and alkali weed (Cressa truxillensis, FACW). Hovore qualifies this observation by writing that, “…nowhere did they form natural stands or create native habitat.” The meaning of this caveat is not clear, but it probably is an indication that these species occurred patchily and at low densities. In response to a request from Coastal Commission staff for an updated wetland delineation confirmed by the California Department of Fish and Game, the City of Huntington Beach sent Kegarice’s (1997) report to the Department with a request for comment. Based entirely on Kegarice’s report, the Department concurred that the



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natural conditions within the region, but occurs in wetlands elsewhere. A positive sign indicates a frequency toward the higher end of the category (more frequently found in wetlands), and a negative sign indicates a frequency toward the lower end of thecategory (less frequently found in wetlands). An asterisk (*) following a regional Indicator identifies tentative assignments based on limited information. From Reed, P.B. Jr. 1988. National list of plant species that occur in wetlands: California (Region 0). U.S. Fish and Wildlife Service Biological Report 88 (26.10). 135 pages. 9 The “County Parcel” was annexed by the City on October 1, 2003.


agricultural portion of the Shea Homes property did not meet wetland criteria (Rempel 1998). Due to the flawed nature of the consultant’s report upon which it was based, the Department’s concurrence adds nothing substantive to the record. Kegarice’s observations that much of the agricultural area supported upland plants in the fall of 1997 has been presented as strong evidence that the site can no longer support the growth of hydrophytes. Bomkamp and Young (2005) emphasized that the “delineation” conducted by Kegarice (1997) was done at the end of a wet cycle when the site was not in agricultural production. They argue as follows:

“TDA/Kegarice did not detect a predominance of hydrophytes and also did not note in her list of dominant plants, the presence of opportunistic weedy species such as salt-marsh sand spurry (Spergularia marina, OBL), alkali weed (Cressa truxillensis, FACW), alkali heliotrope (Heliotropum curassivicum, OBL), and brass buttons (Cotula coronopifolia, FACW+).

These species currently occur on the site but are not predominant, suggesting that their current distribution is in large measure associated with irrigation that was begun with re-initiation of farming after the TDA/Kegarice delineation. This is particularly noteworthy, since between 1999 and the current rainy season, southern California has been in a drought or dry cycle. It is unreasonable that the opportunistic species noted above would not be predominant on a site (if it were a wetland) during a wet cycle with no disturbance (i.e., agriculture) only to appear during a dry cycle with disturbance, without the additional factor, i.e., irrigation.”

Based as it is on false premises (absence of hydrophytes and absence of agriculture), this syllogism is not convincing. First, the authors do not cite Hovore (1997), whose description of the site in November 1997 documented the presence of wetland species, including the sand spurry and alkali weed that were not noted by Kegarice (1997). Second, according to Hovore (1997), the entire site was disked shortly before June 7, 1997 and had only been fallow during that year’s dry season. In southern California, it is not only common, it is characteristic of seasonal wetlands to be invaded by upland plants during the dry season. In this case, the site had been disked after the wet season, and it is quite reasonable that opportunistic wetland species would not be predominant at the end of the summer drought. The 1997 observations by Kegarice and Hovore provide absolutely no evidence that the depressions in the agricultural field cannot support hydrophytes. The 1997 observations also demonstrate that the presence of hydrophytes is not necessarily an artifact of irrigation practices. Wetland scientists from Glenn Lukos Associates (Young & Bomkamp 2004) conducted field work for a wetland delineation within the agricultural area on January 23, March 31, May 24, and May 30, 2003. They concluded that there were “…no areas within the City parcel at the Parkside Estates site that meet the criteria used to define wetlands by any agency.” Their conclusion was based primarily on the lack of indicators of wetland hydrology and the lack of recently formed hydric soil features.



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Delineation within this parcel requires special techniques because it is a “problem area”10 and an “atypical situation.”11 It is a problem area because the soils formed 10 A “problem area” exists where normal conditions make the use of standard field indicators of wetland parameters difficult. At the Shea Homes site, the lack of tidal hydrology is the “new normal” condition (i.e., it is essentially permanent).


under hydric conditions associated with tidal inundation that is no longer present and it is an atypical situation because continuing agriculture prevents the establishment of wetland plants and disrupts the soil column. These factors make wetland delineation difficult for many reasons, including: 1. Vegetation indicators cannot be expected, 2. Hydric soil indicators may be artifacts of prior conditions, 3. The soil surface is frequently disturbed, which removes indicators of recent inundation, 4. Plowing may drastically alter the soil profile, 5. Irrigation might confound the interpretation of the presence of recruiting wetland plants and the presence of indicators of recent hydric conditions. Young and Bomkamp (2004) found no evidence that they thought indicative of wetland hydrology during their investigations. However, most of their samples were taken at times when one would not expect there to have been recent inundation or saturation. During the 32 days prior to their January sample there was essentially no rainfall (0.08”) and the two May samples were taken too late in the season to be informative. The lack of indicators at the end of March is more interesting. January had no rainfall; February was wet with about 2.5 inches of rain from 2/11 to 2/13 and another 1.7 inches from 2/25 to 2/28; March was relatively dry (0.3 inches on 3/4) except for an extraordinary storm that dropped 3.8 inches on 3/16 & 3/17. Despite this deluge, there was no standing water or saturated soil at their sample points 14 days later on March 31. Young and Bomkamp take this as evidence that the site can not support wetland hydrology. However, since several portions of the site have been observed repeatedly to pond for longer than two weeks following similar amounts of rainfall, a reasonable alternative hypothesis is that inundation was relatively ephemeral because the storm occurred late in the rainy season when the land was covered with a dense crop of barley and the rate of evapotranspiration was relatively high. This storm caused extensive inundation of the County parcel that appears from photographs to have lasted between one and two weeks. Under ordinary circumstances, when ponds form and then infiltrate and evaporate, surface indicators are left behind. However, in an area subject to agricultural practices, these indicators are likely to be destroyed. This is very limiting, since a lack of indicators is not necessarily indicative of a lack of inundation. Therefore, direct observations of ponding and saturation are particularly important. On March 31, Young and Bomkamp observed standing water in a 5 ft x 15 ft area at the base of the western slope, but this may have been partially due to dripping irrigation lines. On the same day, they also found evidence of recent ponding in a 2 ft x 20 ft “roadside collection area” next to the flood control channel. These ponding episodes were probably the result of the March 16-17 storm, although the dripping irrigation line is a confounding factor in the western area. They also observed sediment deposits (“light surface crust”) that they noted indicated “past short-duration ponding”12 in two locations (one with a preponderance of wetland indicator species) but concluded there was no wetland hydrology and that the points were not in a wetland.



California Coastal

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11 An “atypical situation” exists where recent human activities (e.g., plowing) or natural events (e.g., fire) have resulted in the lack of positive indicators of one or more wetland parameters. 12 Actually, such evidence does not enable one to estimate the duration of ponding - only that it occurred.


Young and Bomkamp also analyzed several aerial photographs and the rainfall record for the period preceding the photograph to assess inundation. I will discuss their aerial photographic evidence along with the photographic analysis done by LSA in a separate section below. It is well-documented with photographs (Bixby 2005) that the soil on the Shea Homes property has the capability of ponding water for a week to months given the right patterns and amounts of rainfall (e.g., Figures 3 and 6). Young and Bomkamp’s observations provide a mechanism. At the base of the Bolsa Chica mesa at the western edge of the Shea Homes property, they found a clay-rich subsoil at a depth of about 20 inches. This is the general area delineated by the EPA (which includes the area referred to as “AP” in later reports by Glenn Lukos Associates). The clay-rich layer apparently acts as a confining layer, perching water above it. In the depression near the flood control channel (referred to as “WP” in the later reports by Glenn Lukos Associates), a clay loam subsoil was found at a depth of about 22 inches. Bomkamp (2005a), described the area in somewhat different terms with clay-loam in the upper 9-20 inches and coarser material below. The clay-loam also acts as a confining layer. Young and Bomkamp also noted shallow redoximorphic features in several areas. Most of their sample points in the areas delineated as a wetland by EPA and others had low chroma soil near the surface and mottles13 between 13 and 30 inches below the surface. On the data sheets, these points were first noted to have hydric soils; later this was crossed out and the soils were noted as not hydric with the remark that the features were relicts due to hydrologic alterations of the site. It is likely that some of these features did form during the period when the site was a tidal salt marsh. However, the fact that they did not observe field indicators of hydrology in 2003 is scant evidence that the site has been so hydrologically altered as to preclude frequent soil saturation for a duration sufficient to promote hydric soils. The fact of the matter is that any inferences drawn from the existing soil features that they have described will necessarily be equivocal due to the history of the site and the continuing disturbance from farming. In their discussion, Young and Bomkamp make the point that since redoximorphic features were identified “…within the tillage zone, in an irrigation-induced perched water table…, it is apparent that such features could form elsewhere on the property if reducing conditions had occurred for sufficient duration….” This was not observed. Although this is an appropriate type of comparison, it should not be considered in a vacuum. Areas where oxidized root channels14 were not observed in 2003 had been inundated for over a month during the winter of 2000 - 2001 (Figure 3) and during other periods in the past. Under most circumstances, oxidized root channels and other redoximorphic features would tend to form under prolonged reducing conditions, and should still have been visible two years later, but were not found. Unfortunately for the delineator, there are many reasons why such features might not form despite the



California Coastal

Commission

13 During periods of soil saturation, iron may be leached from the soils producing a dark coloration or “Low chroma”; soils that are subject to alternating periods of saturation and drying develop iron concentrations or “mottles.” 14 Under prolonged saturated soil conditions, a toxic environment is created. Some plants have the ability to release oxygen through their roots creating a safe microenvironment. This results in iron oxidation (i.e., rust) on the walls of the root channel or “rhizosphere.” Hence, if a live root is present, “an oxidized root channel” is considered evidence of recent soil saturation.


presence of anaerobic conditions (e.g, low iron concentration), and if they did form, soil disturbance due to repeated plowing and disking might make them difficult to observe. Young and Bomkamp argue that the observation that upland species were predominant on November 20, 1997 “in the absence of farming and with above average precipitation” is evidence that upland vegetation would establish in the absence of farming and that the presence of scattered wetland plants in 2003 must have been a result of irrigation. I have already pointed out that there actually was not a substantial absence of farming in 1997, since the area had been disked in the late spring, and that wetland species were, in fact, present. With regard to the “above-average” precipitation, there had been no rainfall from February 14 to November 11, 1997. From the 11th to the 14th of November a storm brought about an inch of rain. One would hardly expect this event to affect the character of the vegetation viewed six days later. In summary, Young and Bomkamp (2004) found no evidence of wetland conditions on the city portion of the Shea Homes property during the course of their investigations. They based their delineation on an assessment of soil features that are subject to various interpretations and on an assessment of hydrology based on very few data. In my opinion, the available evidence did not justify their strongly worded conclusion that no areas meet the wetland definition of any agency. Coastal Commission Staff Analysis Hydrology Photographic Evidence of Inundation

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#K 15 of 99

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There are additional analyses that one could do with the photographic record available on Bixby’s (2005) website and, because many of the descriptions on the website are somewhat hyperbolic, I believed that an independent assessment was necessary. I asked the applicant to analyze these photographs. Unfortunately, I did not find their consultant’s analysis (Bomkamp and Young 2005) useful for several reasons. First, portions of the record were rejected in a blanket fashion because the photographs were taken during a year of unusually high rainfall or during a period that included unusually high monthly rainfall totals. I think this approach is much too crude. Even during a wet year there may be periods that are not unusual and drying patterns may also be informative. For example, heavy rainfall in November or December may be many times greater than normal for those months, but well within the bounds of normal variation in January or February, and so quite informative, especially since the ground would generally not be charged from earlier storms. Second, the significance of photos of the AP area was denigrated because that area is “along the outer edge of the field where heavy farm traffic occurs,” and “ponding is caused by artificial compaction at this location.” Although presented as fact, the latter is really an ad hoc hypothesis. Since inundation often extended well into the plowed area, I am not convinced of the truth of their hypothesis. Third, the description of the photographs by the Glenn Lukos biologists did not always correspond to my perceptions. For example, they described the inundation shown in Figure 6 as follows: “The first measurable ponding started on 02/26 and persisted over very small areas (i.e., a few square feet until March 11) for 14


days of ponding over a very limited area.” “Conclusion: …this area does not support a positive finding for wetland hydrology with (sic) possible exception of an area covering a few square feet; however, soil compaction and alteration of the soil structure indicate that this is (sic) not support a finding of wetland hydrology.” It appears to me that the photographs show 8 days of inundation over a large area and 14 days of probable soil saturation over a slightly smaller area in a tilled depression and not just on the compacted road. The alteration of the soil structure is due to the atypical situation associated with farming and not germane unless it permanently drained the soil, which it obviously has not done. I believe that this series of photographs does, in fact, support a finding of wetland hydrology. Finally, Bomkamp and Young (2005) focused their report on a critique of the assertions of Mr. Bixby that accompany the photographs on his web site. Mr. Bixby is a citizen activist and not a wetland scientist. His important contribution has been his acquisition and presentation of the photographs, not his layman’s analysis of them. In short, the Glenn Lukos report was not the independent, objective analysis of the available photographs that I had hoped for. Therefore, I have attempted such an analysis myself. I analyzed the photographic record to investigate three related questions: 1. What patterns and amounts of rainfall result in inundation for long duration15? 2. For the 20-year period since 1985 (by which time all hydrological modifications had taken place), is there evidence of frequent (> 50% of all years) long-duration inundation? 3. What is the probable frequency distribution of ponding of various durations (<7 d, 7-14 d, 15-30 d, >30d). I chose seven days as the significant inundation event because the Army Corps of Engineers and the National Resource Conservation Service recognize seven days of inundation as the minimum period that could result in reducing conditions for a sufficient duration to promote the formation of hydric soils. Similarly, the EPA (1989) found that, “…inundation or saturation must meet or exceed a duration of 7 continuous days during the growing season in order to support hydrophytic vegetation and to exclude upland plant species (Sipple 1988).”



California Coastal

Commission

Not surprisingly, there are problems with this informal photographic record. Ground-level photographs are challenging to interpret because: 1. Photographs were obtained in an ad hoc or haphazard fashion, so they do not uniformly sample the rainy season each year, nor do they uniformly sample the site spatially. 2. They are not taken from the same vantage points nor is the focal length of the lens the same in each instance. As a result, one photograph may capture a large area and the next photograph in a temporal sequence may include only a portion of that area. Therefore, apparent changes over time may be difficult to generalize over space. 3. Because the field is plowed, the angle of the line-of-sight relative to the furrows determines what can be seen. Standing water between furrows is hidden when looking across the plow line. 4. When crops are mature they provide 100% cover in the agricultural area and prevent the after-the-fact assessment of inundation from photographs. Aerial photographs may also be difficult to interpret. In some cases, standing water shows as a reflective surface, which is usually distinctive. However, standing water is generally dark in photographs and sometimes difficult to distinguish from wet soil or shiny dry surface crusts. In several instances, LSA interpreted aerial photographs as showing standing

15 “Long duration” is defined as continuous inundation for 7 days to one month. “Very long duration” is defined as continuous inundation for greater than 30 days.


water following a period when there was little or no rainfall and characterized these interpretations as “false positives.” There may also be some cases of false negatives where inundation was not identified. Despite these shortcomings, the existing photographic record (Bixby 2005 and aerial photos obtained by the applicant’s consultants) contains a great deal of useful information and provides the only data in addition to the rainfall record that can be used to estimate the frequency and duration of ponding on the Shea Homes property. Pattern of Rainfall Necessary to Result in At Least 7 Days of Inundation Although the pattern and amount of rainfall that occurs at Bolsa Chica is central to this discussion, it is important to understand that, as for most locations, site-specific information is not available. However, rainfall is recorded at several nearby locations. Average annual rainfall at coastal stations within about 15 miles ranges from about 10 inches to about 13 inches. Bilhorn (1987, 1995) used the data from the Lake Street Fire Station in Huntington Beach, which is about 2 miles from the site. For the period 1929 - 1994 the median annual rainfall was 10.27 inches. Record keeping at this station ended in 2001. I have used rainfall data from the Los Alamitos Station (LSA 2005), which is about 5 miles from the site. For the period 1958 - 2005, median rainfall at Los Alamitos was 9.04 inches and the average rainfall was 9.99 inches. Data from either of these stations provides a reasonable index of the rainfall at Bolsa Chica (i.e., the days of rainfall will be nearly identical and the amounts of rainfall will be well-correlated). I have analyzed the ground-level photographs posted on the web and submitted to the Coastal Commission by Mr. Mark Bixby in order to try to characterize the pattern of rainfall necessary to result in inundation for at least seven consecutive days. This is possible because, during several years, there are multiple ground-level photographs separated by days or weeks. Some of these photographs were taken during years of greater than normal rainfall. However, for those years, I have only used those photographs that were taken during a period when the pattern of precipitation was similar to what is commonly observed in January and February16, and not following prior heavy rainfall. The results are presented in Tables A2, A3, A5 and A8 in Appendix A. The shaded portions of the rainfall columns (lighter shading where two shades are used) are periods that represent patterns that would not be unusual for January or February and where rainfall earlier in the season was not so extreme as to bias the analysis. The shaded portions of the columns that contain descriptions of inundation for areas WP, AP, and



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Commission

16 In Tables A2, A3, A5 & A8 and in discussions with the applicant’s consultants I have referred to such a pattern as “near normal.” This determination is subjective and based on an examination of the existing record and an assessment of both the amount and timing of particular rainfall events. LSA (Homrighausen 2005) commissioned Exponent to conduct a statistical analysis of the rainfall record to assess my determinations. Exponent found that the rainfall in October 2004, which I had treated as “near normal,” was unusual by their criteria. I disagreed based on the rainfall data from the Costa Mesa Station, which was all that was available until recently. However, based on the higher rainfall recorded at the Los Alamitos Station, I have not treated the early 2004 rainfall as “near normal.” Exponent’s analysis was not provided for critique and Homrighausen did not comment on the four tables used in my current analysis.


the County wetlands indicate periods that demonstrate long duration ponding. Several of the descriptions contain rough estimates of the size of the ponds. These estimates were made by scaling off distinctive features in the photographs. Plowed furrows were assumed to be 2 feet from center to center (probably an underestimate), the distance between fence posts along the flood control channel was assumed to be 6 feet, and the distance between parallel tire tracks was assumed to be 5 feet. In addition, the distance between some topographical features was scaled off the Hunsaker (2004) map. These estimates were done quickly and are subject to many sources of error. They are probably generally underestimates, but at least give some rough idea of the relative size of the ponds that formed following rainfall events. Area WP was inundated for long duration during each of the five years for which there are data. In general, area AP seemed to pond less readily and dry somewhat more quickly, but was, nevertheless, inundated for long duration during two of the three years for which there are data. The County wetland was also inundated for long duration for two of the three years for which there are data, but not the same years as AP. These data demonstrate that all three areas are capable of long duration ponding during periods of near normal rainfall. In general, long duration ponding appears to require a storm that drops two or more inches of rainfall after the ground has previously been partially charged with water by earlier precipitation events. The observance of such a pattern or more extreme rainfall was the basis for inferring long duration ponding during periods for which there were no photographs available. Estimation of the Frequency of Long Duration Ponding Since 1958 The standard for wetland hydrology that I have applied is frequent inundation for at least seven consecutive days. The Corps defines “frequent” as occurring more than half the time (i.e., at least 51 out of 100 years, on average). All available data must be used to assess the record under this standard. Throwing out extreme years or extreme rainfall events would bias the result downward. If long duration ponding occurs during all years that have the median rainfall or greater, then this standard is met by definition. The years with greater than median rainfall will include mostly near normal rainfall, but will also include many extreme periods such as El Nino years. The point is that for judging frequency, the entire record must be used.



California Coastal

Commission

I used all the available aerial and ground-level photographs in conjunction with the rainfall record17 for the period 1985 through 2005. I only included areas WP and AP in this analysis. I did not analyze photographs taken of the road adjacent to the residential development to the north, the former stable area, the bare staging area at the western edge of the fields, or the road along the toe of the flood control channel, when it existed. These areas have all been subject to compaction and all but the former stable area are essentially roads. I only used photographs taken after 1985, because the hydrological modifications associated with the construction of the Cabo del Mar condominium complex were completed by that time and, to my knowledge, there have been no

17 All rainfall data (LSA 2005) for the period 1958 - 2005 come from the Los Alamitos station (Orange County Environmental Management Agency Station 170).


additional significant off-site modifications that would affect the hydrology of the Shea Homes property. There is at least one photograph available for each of the 20 rain years (October through March for this analysis) since 1985. For each rain year for which there was an aerial photograph I tabulated the rainfall data (Appendix A: Tables A1-A20) and assessed whether the rainfall data provided strong evidence of periods when ponding was likely. I analyzed the ground-level and oblique aerial photographs myself. I used the results of the analyses conducted by LSA and Glenn Lukos Associates for the vertical aerial photographs. For the period and area of interest, the results were the same for the subset of photographs that both groups analyzed. I have summarized the results of my analysis in Table 1. LSA (Homrighausen 2005) believes that the entire available record should be used for this determination. They have obtained aerial photographs and rainfall data for the period 1958 through 1985 and conducted an analysis similar to that described above (Appendix B: Tables B1-B27)18. However, the hydrology criterion they recommend applying is inundation for at least 14 days. Although aerial photographs were occasionally useful, most of their inferences regarding inundation were based on the observed pattern and amount of rainfall using criteria that were not discussed. In general, I am in agreement with their estimates of when inundation occurred. In most cases, they did not explicitly estimate the duration of inundation during each year. I have annotated their tables with my estimate of the duration of inundation for each year and have summarized the results of my analysis for this period in Table 2. Rainfall and Probable Inundation During the Period 1958 - 2005 During the 20-year period from winter 1985 through spring 2005, the available evidence suggests that WP was inundated for long duration in each of 12 years and area AP was inundated for long duration in each of 11 years (Table 1). The pattern and abundance of rainfall suggests that WP was inundated for 7-14 days during 4 years, for 15-30 days during 3 years, and for more than 30 days during 5 years. LSA concluded from their analysis of aerial photographs that during the 27-year period from winter 1958 through spring 1985, area AP ponded following significant rainfall but area WP generally did not until after about 1973. Based on their examination of historical aerial photographs, LSA did not find evidence that a topographical depression existed in the area of WP in the early years of the record. Based partly on photographic evidence, but mainly on the pattern and abundance of rainfall, LSA concluded that ponding occurred at area AP during 13 years and at area WP during 5 years of the 27-year record19 for unspecified durations. Based on the pattern and



California Coastal

Commission

18 Exponent (Jordan 2006a) took the analysis a step further and extrapolated rainfall back to 1770. They then fit the data to a probability density function and estimated the proportion of years that would have rainfall of various amounts. Although an enjoyable read, I don’t think the analysis adds anything to the discussion. The actual available data are more germane. 19 Actually in Appendix B, Table B28, the figures are 12 years and 4 years, respectively. However, this appears to be a mistake because Table B23 clearly indicates that both areas appeared inundated in photographs 15 days after


abundance of rainfall, I conclude that during that period, area AP and any other significant topographical depressions that may have existed were inundated for 7-14 days during 9 years, for 15 - 30 days during 5 years, and for greater than 30 days during 4 years, for a total of 18 years during which there was continuous inundation for long duration (Table 2). In general, years during which there was no long duration ponding received less than the median rainfall (Table 3). There was only one instance when the rainfall pattern suggested a lack of significant inundation even though the amount of rainfall was greater than the median. The reverse is not true, however. Continuous ponding for seven days or more probably occurred during seven of the years that received less than median rainfall. Both these observations demonstrate that the distribution of rainfall is more important than the annual total in determining whether long duration ponding occurs, especially for the middle 50 percent of rain years (6.5” -12.3”). The lower and upper 25 percent of rain years are, respectively, seldom or always inundated for long duration. This pattern is also apparent when one compares the estimated duration of ponding during years of differing rainfall (Table 4). During very dry years, inundation is generally ephemeral and during very wet years, there is generally extensive ponding for very long duration (>30 d). The estimated duration of ponding is more variable during years of intermediate rainfall. The 1987 Army Corps of Engineers Wetland Delineation Manual defines wetland hydrology as inundation or saturation for at least 5% of the growing season (18.5 days in coastal California). However, this standard is not applied in routine delineations, which only require field evidence of inundation or saturation at the time of the site visit. The Coastal Commission does not have a quantitative standard for hydrology. Rather, the requirement is relative. Wetlands are those areas that are inundated or saturated at a frequency and duration sufficient to promote the formation of hydric soils or to support a predominance of hydrophytes. The evidence reported above indicates that the two areas in question (referred to as WP and AP herein) were inundated or saturated at a frequency and duration sufficient to promote the formation of hydric soils and to support a predominance of hydrophytes based on a 7-day standard for inundation. However, that does not necessarily mean that hydric soil conditions actually developed or that hydrophytes would predominate in the absence of farming. The following analysis addresses those questions. Wetland Soils



California Coastal

Commission

The National Resource Conservation Service has formed the National Technical Committee for Hydric Soils to develop criteria for identifying and mapping hydric soils throughout the United States. The accepted definition of a hydric soil is “a soil that formed under conditions of saturation, flooding or ponding long enough during the growing season to develop anaerobic conditions in the upper part” (59 Fed. Reg. 35680 07/13/94). An accepted field indicator of hydric soils is frequent ponding for long

the beginning of a rainy period, and the text reads, “Likely at least AP area was ponded for 15 days or more in March.”


duration. Based on this indicator, areas AP and WP are estimated to be ponded long enough and often enough to promote the formation of hydric soils. The actual duration of ponding or saturation that results in anaerobic conditions is variable and dependent upon many factors, but four general conditions are required20: 1. Inundation or saturation that excludes atmospheric oxygen, 2. Organic tissues, 3. An active microbial population that is oxidizing organic tissues, and 4. Stagnant or near stagnant water (moving water tends to carry oxygen). The applicant’s technical consultants have questioned whether 7 days of ponding is sufficient to result in anaerobic conditions in the upper 12 inches of the soil at AP and WP. To test this hypothesis, they applied a chemical test to saturated soils to directly assay for anaerobic conditions. The sampling stations and monitoring wells referred to in the text are shown in Figures 9 - 11. Although there was relatively little precipitation during the 2005-2006 rain year, ground water was anomalously high throughout Huntington Beach due to the lagged effects of extremely high rainfall during 2004-200521. Data from test wells demonstrate that groundwater at Parkside rose from about -6 feet (Mean Sea Level) in September 2005 to about +0.5 feet (MSL) by December and remained at that level through at least March 2006 (Castle 2006).22 Although the observed shallow groundwater has little relevance to the pattern of inundation and shallow soil saturation during most years, it did provide an opportunity to directly assess reducing conditions in saturated soils in the County parcel and in area AP. The shallow soil at WP was never saturated by high groundwater. Glenn Lukos Associates began soil testing on January 12, 2006 using the chemical alpha, alpha’-dipyridyl, which develops a reddish-purple color in reaction with ferrous (reduced) iron. On January 12, the soil at the sample site at the County parcel was already saturated by ground water at 12-15 inches below the surface and the presence of ferrous iron demonstrated anaerobic, reducing conditions. The soil above 12 inches was not saturated (moist-wet) and was oxygenated. This pattern persisted through March 15, except that from February 15 through at least February 24, the soil was saturated and reduced up to 6 inches below the surface. Since on February 10, the soil at 6 inches was only moist to wet and still oxygenated, this indicates that the soil became saturated and then anaerobic and reduced to the point of iron reduction in fewer than 5 days23. The six sample sites at AP showed a more complicated pattern of soil saturation. These sites were first visited on January 12 (AP4,5 & 6) or January 20 (AP1,2 & 3). At that time, the soil from 12-15 inches below the surface was saturated, but did not show iron reduction. The soil at several stations was saturated above 12 inches and several



California Coastal

Commission

20 Vepraskas, M.J. and S.P. Faulkner. 2001. Redox chemistry of hydric soils. Pages 85-105 in J.L. Richardson and M.J. Vepraskas, editors. Wetland Soils. Genesis, Hydrology, Landscapes and Classification. Lewis Publishers, NY. 21 Highest rainfall on record (23.39 inches) with an estimated return period of 48 years (Jordan, 2006b). 22 Pacific Soils’ wells MW-3, MW-17, and MW-19. 23 This is very fast and may contain significant sampling error (as could any of these estimates). Since samples were not taken from the exact same location on each date, small scale spatial variability is necessarily confounded with temporal changes. Small scale spatial variability was not formally estimated.


stations also had surface ponding and shallow saturation separated from the deeper saturation by a band of merely moist to wet soil. A plausible explanation is that ground water rising under pressure would generally be confined by the shallow clay layer, but in scattered areas where coarser material was present, water would reach the surface and then spread horizontally above the clay layer (T. Bomkamp, personal communication 06/02/06). There was essentially no evidence of iron reduction at the AP stations during the period January through March. At four of the sample sites, the soil remained saturated until February 8. Saturation was observed for a week or two longer at the other two sample sites (AP1 & AP3). In general, there was no evidence of iron reduction within this depth stratum in the AP area. Although occasional soil samples tested positive for reduced iron, the soil from nearby pits tested negative. In summary, after a period of soil saturation ranging from at least 19 days to at least 35 days, there was no evidence of iron reduction at a depth of 12 to 15 inches at 6 locations in area AP, whereas soil at the same depth at a single site in the County parcel was continuously reduced. Large portions of area AP were also inundated and the shallow soil saturated for long periods. The soil at sample site AP1 appears to have been saturated in the upper 6 inches from about January 20 until about March 6 with no evidence of iron reduction. The soil was moist-wet and presumably oxygenated for 2 to 5 days in early March and then became saturated again. Reduced iron was present 6 to 9 days later and was considered the predominant condition after about 2 weeks. A partial explanation for the differences observed at the two sample sites may be that the pressurized ground water that caused soil saturation and ponding at AP was oxygenated and did not remain stagnant long enough to result in anaerobic conditions. However, by late February the ground water was receding and ponded surface water should have been stagnant. Nonetheless, after about 2 to 4 weeks of soil saturation no ferrous iron was detected other than at AP1. About an inch of rainfall on April 1 resulted in extensive ponding both at the County parcel and at AP. This provided another opportunity for examining the time required for iron reduction to occur. Sampling took place on April 21 and on May 2 (AP) or May 5 (County). At the County parcel, the upper 4 to 8 inches of the soil column at most stations showed evidence of reduced iron after 17 days, whereas only 1 of 3 replicates at 1 of 5 stations at AP tested positive for ferrous iron. After 28 days, most stations in both the AP and County areas showed evidence of iron reduction in the upper part of the soil column. In summary, it apparently requires between 5 and 17 days of soil saturation or inundation for the onset of iron reduction in the near-surface soil in the County parcel. The analogous figures for area AP are 14 and 28 days. No explanation has been proffered for the striking difference in the duration of saturation necessary to result in the reduction of iron between the County parcel and the nearby AP area.



California Coastal

Commission

Understanding the mechanisms producing the observed differences at the two sites is important because the definition of hydric soils is not based on iron reduction, but rather on anaerobiosis.24 Anaerobic conditions are necessary for iron reduction, but the lack

24Fontaine (2006) made this point. Josselyn (2006b) responded that the National Committee on Hydric Soils Technical Note 11 requires anaerobic conditions to be demonstrated by documenting iron reduction. However,


of iron reduction is not evidence that soil is aerobic25. There are two concerns. First, there is a lag of unknown duration between the time the soil becomes anaerobic and the initiation of iron reduction. I have not been able to find a discussion of this time course in the literature, but plots of the changes in redox (oxidation-reduction) potential26 with time in Vepraskas and Faulkner27 suggest that (at pH 5) it could be at least a few days to 2 weeks from the onset of anaerobic conditions to the initiation of iron reduction. Under favorable conditions,28 Vepraskas (personal communication 07/26/06) estimates that the lag may be as short as 1 to 5 days. The second concern is that iron reduction may not be apparent despite a low redox potential. This could occur if iron concentrations were low. The soil concentration of iron is much higher at the County parcel (787 ppm) than at AP (225 ppm) or WP (31 ppm). Although alpha, alpha’-dipyridyl appears to be sensitive to extremely low concentrations (<1 ppm) of iron salts in water29, I have not been able to find literature that quantitatively relates the concentration of iron in the soil to the alpha, alpha’-dipyridyl test. It may be that any of these concentrations are sufficient to produce a positive test under reducing conditions or, given these low concentrations of iron, it may require a longer time to produce a positive chemical test. Dr. Michael Vepraskas, a wetland soil scientist at the North Carolina State University, studies oxidation-reduction reactions in saturated soils. His work on soils30 that are always above 5o C (as are California coastal soils) has shown that the time required for a saturated soil to become anaerobic is strongly related to the amount of organic carbon that is present (personal communication, 07-19-06). Where total organic carbon (TOC) is 3% or greater, it generally requires 1-4 days for the soil to become anaerobic. Where TOC is less than 3%, the time required increases rapidly with a decrease in TOC and may range from 3 - 50 days. The time to iron reduction is no doubt also inversely correlated with the amount of organic carbon present. The percent dry weight organics in Table 8 was estimated by the soil laboratory by multiplying TOC31 by a conversion factor.32 I used this factor (1.8) to convert back to TOC (Table 8). Differences in TOC probably explain much of the variability observed in the chemical testing for reduced iron. There also are significant differences among



California Coastal

Commission

Technical Note 11 provides Technical Standards for the development of field indicators of hydric soils (which are generally based on iron reduction) and is not intended to modify the definition. Josselyn also seems to confound aquic conditions (which require iron reduction) with hydric soils (which only require anaerobic conditions). 25 Vepraskas, M.J. and S.W. Sprecher. 1997. Overview of aquic conditions and hydric soils. Pages 1-22 in M.J. Vepraskas and S.W. Sprecher. Aquic conditions and hydric soils: The problem soils. Soil Science Society of America, Madison, Wisconsin 26 Redox potential (Eh) is a measure of the tendency of chemical substances to be reduced (i.e., to acquire electons) and is measured in mV. A low Eh indicates a reducing environment, whereas a high Eh is characteristic of an environment that favors oxidation. 27 Vepraskas and Faulkner, op.cit. 2001. 28 Carbon levels above 3%, continuous soil saturation, soil pH <7, and low concentrations of nitrate or Mn oxides. 29 Moss, M.L. and M.G. Mellon. 1942. Colorimetric determination of iron with 2,2’-Bipyridyl and with 2,2,’2”-Terpyridyl. Industrial and Engineering Chemistry 14:862-865. 30 The pH in the soils that were studied varied from about 4.0 to about 5.5 (personal communication, 07-26-06). 31 Obtained by wet extraction and titration using the Walkely-Black method. 32 Telephone conversation with Jim West (Soil and Plant Laboratory, Inc.) on July 19, 2006.


sites. Estimated TOC33 ranged from 0.8% to 7.1% at the County area and from 1.6% to 5.4% at AP, but was about 1% or less at all the rest of the sample locations, including WP (Table 8). At AP the mean and median were both about 3%. At the northeastern portion of the reference area at the County parcel where surface inundation was observed, TOC varied from 0.8% to 1.2%. Differences in soil pH may also contribute significantly to the observed variability in iron reduction because soils with higher pH become reducing at a lower redox potential (and therefore after a longer time) than soils with a lower pH. The average soil pH (Table 8) was about 5.7 in the County parcel (range: 4.1 - 7.0), 7.0 at AP (range: 6.1 - 7.5), and 7.5 at WP (range: 7.3 - 7.6). The other wetland areas averaged 6.4 to 7.1. At the northeastern portion of the reference area at the County parcel where surface inundation was observed, pH varied from 6.4 to 6.8. Although there remains considerable uncertainty in the estimates of the time required for the development of anaerobic conditions, the available evidence suggests that it likely requires more than 7 days of saturation or inundation for anaerobic conditions to develop at AP and WP, probably due to the relatively low organic content of the soil at WP and the relatively high pH at both locations.. Therefore, I conclude that it is more likely than not that during most years areas WP and AP are not ponded for the duration needed to promote the formation of hydric soils at those locations, given the nature of the soils present. Wetland Vegetation (Atypical Situation) The agricultural operations on the Shea Homes Parkside property make wetland delineation difficult because they remove all natural vegetation, repeatedly disturb the soil, and supplement rainfall with irrigation during dry periods. Therefore, the standard indicators of wetlands contained in the Corps of Engineers 1987 Manual may be missing or masked and, because of irrigation, the periodic appearance of hydrophytes may sometimes be difficult to interpret. With regard to vegetation, the Corps suggests examining nearby unaltered areas that otherwise appear similar. I believe such comparisons are appropriate for atypical situations and, at least from a state perspective, the agricultural portion of the Shea Homes property is an atypical situation.34 At my request, Glenn Lukos Associates (Bomkamp et al. 2005; Bomkamp 2005a) examined the vegetation and soils in nearby areas that were similar in elevation to two depressional areas in the agricultural field. Glenn Lukos Associates compared the depression adjacent to the flood control channel (Wintersburg Pond or WP), the



California Coastal

Commission

33 As percent oxidizable organic carbon (Hess, P.R. 1971. A Textbook of Soil Chemical Analysis. John Murray, London as referenced in Beaudoin, A. 2003. A comparison of two methods for estimating the organic content of sediments. Journal of Paleolimnology 29:387-390.). 34 From a federal perspective, once an agricultural area is designated as “prior converted cropland,” the lack of wetland vegetation is automatically treated as the “normal situation” and thus renders the area not subject to Corps regulation. However, the Corps considers this designation provisional since RGL 90-07 states that if prior converted cropland is abandoned and wetland conditions return, the area is again jurisdictional. In other words, the process of designating an area as prior converted cropland is subject to error.


western depression (Agricultural Pond or AP35) and two areas in the County parcel roughly matched by elevation36. The sampling stations and monitoring wells referred to in the text are shown in Figures 9 - 11. Vegetation was examined along two wetland transects in the County parcel, and visually assessed in the areas that tend to pond water at AP and WP.37 At the County parcel, the seven sample plots (C1-C7) that were matched with the depression at WP each had a predominance of hydrophytes and were dominated by some combination of pickleweed (OBL), saltgrass (FACW), alkali heath (FACW+) and little seed canary grass (UPL). Similarly, the seven sample plots (D1-D7) matched with area AP were either bare or had a predominance of hydrophytes, including some combination of saltgrass, alkali heath, pickleweed, and Torrey’s seablite (FAC+). Although acknowledging that these results suggest that the depressions in the agricultural area could potentially support a predominance of hydrophytes, Bomkamp et al. (2005) then argue that atypical methodology should not be applied because the area is a “prior converted cropland,” a jurisdictional appeal that is only germane under federal law. They also argue that such a comparison is deceptive because they believe that wetland hydrology has been eliminated from the agricultural portion of the Shea Homes property as a result of construction of levees, land-leveling, and diversion of water from upstream areas due to residential development. However, the areas on the County parcel that were delineated as wetlands (Sanders 1987, 1994; Huffman 1987; EPA 1989)38 appear to have suffered similarly severe alterations to hydrology as the City parcel. They have also suffered similar types of soil disturbance, although for many fewer years. Hovore (1997) reported that nearly the entire area was disked in 1997, completely removing all traces of the surface vegetation except in a few small areas. He also characterized the County parcel as “partially filled and entirely graded-over.” Photographs taken by Coastal Commission staff in fall 1998 show that the County parcel from the tree line to the toe of the berm for the flood control channel and from the elevated oil pipeline east to the City parcel had been disked, roughly leveled, and 100% of the vegetation removed (Figure 4). By October the area was plowed and from December 1998 through at least April 1999, fill was deposited on the field adjacent to the Eucalyptus trees and a palm tree. Despite these extreme environmental insults, by September 2000, some portions of the site once again supported a predominance of hydrophytes (Harrison 2000) and the site had further developed wetland characteristics by April 2002 (LSA 2002). Although



California Coastal

Commission

35 “WP” and “AP” are simply short-hand designations coined by Glenn Lukos Associates for two general locations for which there is empirical evidence of ponding after rain storms. “AP” is variously used to refer to the general area of the EPA delineation at the western side of the site or to the current depression at the base of the western hillside and does not refer to a pond created for agricultural purposes.. 36 In fact, the low areas that pond water at AP and WP were not quantitatively sampled for vegetation. Transects A and B were west of WP and much higher. Transect E began in the area that ponds water and extended northeast over higher ground. However, the areas sampled at the County parcel for reference were at roughly similar elevations to those areas at AP and WP that pond water. 37 The three dominant species (brass buttons, FACW+; salt marsh sand spurry, OBL; and rabbitsfoot grass, FACW+) in the WP were all wetland indicators. On April 6, the AP was still inundated and had no emergent vegetation. Later, a few individuals of brass buttons and bristly ox-tongue (FAC) had appeared. However, as pointed out by Bomkamp et al. (2005) observations of wetland plants on the City parcel are difficult to interpret due to the extreme rainfall of 2005. 38 Referring to EPA (1989), LSA (2002) incorrectly asserts that “…none of the County parcel was included in the wetland determination.” Both Sanders (1987; Figure 3) and EPA (1989; Figure 9) map wetlands on the County parcel and Huffman (1987; Figure 6) includes the County parcel as an area “…exhibiting wetland hydrology, soil and vegetation conditions.”


wetlands are no longer found where they were delineated in the 1980s, in the absence of soil disturbance they are developing and expanding into existing depressions (Fontaine 2005b) and water tends to pond in depressions (e.g., Figure 5). I tested the hypothesis that the City parcel has suffered greater hydrological alterations than has the County parcel (and hence that the latter provides a poor comparison for the former). If this hypothesis is true, then the agricultural depressions should be inundated and saturated less frequently and for shorter durations than the County parcel wetlands. I conducted this test by comparing the patterns of inundation and drying in the three areas using photographs from the Bixby (2005) website. There are several series of photographs of the three areas that were taken at about the same time and that allow direct comparisons of actual inundation and drying under identical rainfall conditions. At the County parcel, the area within the photographs is south and west of a palm tree (Figures 4 & 5) that provides a spatial referent and appears to include portions of polygons characterized as “pickleweed/sea-blite scrub” in 2002 (LSA, 2002) and to be adjacent to sample points C1 and C2, which were dominated by pickleweed in 2005 (Bomkamp et al. 2005). I only used photographic series within which the palm tree and a particular pattern of tire ruts was visible (e.g, Figure 5). The results of this analysis are shown in Tables A1-A3 and A8 in Appendix A. It appears that when the depression near the palm tree in the County parcel is inundated, so are portions or all of the depressions within the agricultural area that are designated AP and WP. Ponding within the depression at the reference area appears to wax and wane with rainfall and drying conditions roughly in the same pattern as at AP. WP seems generally to stay wetter longer. However, in winter 2002-2003, the reference area held water longer than either agricultural area. Some of this year-to-year variability may be related to changes in drainage patterns resulting from agricultural practices. The available data suggest that the wetlands in the County parcel and the potential wetlands in the agricultural area are at approximately the same elevations, are depressions relative to the surrounding topography, have a shallow clay-rich confining layer, and have similar surface hydrology. The available data falsify the hypothesis that the County parcel is a poor reference site because it is significantly wetter than the City parcel due to surface inundation.



California Coastal

Commission

A second argument is that the hydrology of the County parcel is qualitatively different from that of WP or AP. LSA (2002) installed 16 monitoring wells in the County parcel in December 1999 and recorded the depth to standing water between December 1999 and May 2000 and between December 2001 and March 2002. Three wells (10, 13, & 14) close to the flood control channel were examined 3 times at 3-hour intervals on a single day and fluctuations in water height suggested some tidal influence. LSA concluded that the hydrological regime within the study area is primarily a function of surface water following rainfall that causes rapid, though generally brief, rises in groundwater. Only wells 10 and 13 had groundwater within one foot of the surface for long duration. However, groundwater also rose to within a foot of the surface immediately following rainfall on one or two occasions at LSA wells 9, 14, 15, and 16, which are all within the County parcel. In general, the depth to groundwater increases with distance from the flood control channel (Table 5).


In order to examine further the degree to which hydrology in the County area is a function of recent rainfall, I correlated the change in the depth of groundwater from the previous (roughly weekly to biweekly) observation with cumulative rainfall during the previous 7 or 30 days (Table 6). There were no significant correlations with 30-day cumulative rainfall. However, change in the depth to groundwater was significantly correlated with 7-day cumulative rainfall for all but 2 wells (6 & 8). However, the proportion of the variability in water depth that is explained by the variability in recent rainfall (r2) was small for wells 10, 12, and 13. As suggested by LSA, it is likely that the area represented by these wells is affected by water in the flood control channel and that this affect is most pronounced close to the channel berm. It is also clear that ground water is closer to the surface near the channel, as represented by LSA wells 10 and 13 (Table 5). For these reasons, I agree that the wetland area mapped by LSA (2002) and sampled by Bomkamp et al. (2005; Transect D) does not provide a good reference area for vegetation. However, the area between LSA wells 8 and 9 that supports pickleweed and seablight scrub (LSA 2002; Bombkamp et al. 2005) does not appear to be dependent on high groundwater for hydrology. In fact, although there are few common dates, the depth to water at LSA well 9 appears roughly comparable to or greater than the depth to water at the Pacific Soils well 8 adjacent to area WP (Tables 5 & 6). This portion of the County parcel is the same area that I used to compare to areas AP and WP for timing and duration of inundation. Therefore, I think it is reasonable to conclude that, like this portion of the County parcel, areas AP and WP are inundated or saturated at a frequency and duration sufficient to support the growth of hydrophytes; and, in the absence of farming, would support the growth of hydrophytes.


ApplicationHNB-MAJ-

No.: 1-06

Ca

lifornia Coastal Commission

The applicant’s consultants have objected to this conclusion based on differences in soil chemistry (Table 8). They interpret these differences as evidence that the County parcel has been structured by wetland processes, and that AP and WP have seldom been subject to saturated soil conditions. Most of these arguments are presented by Josselyn (2006a) and are based largely on theoretical considerations. For example, Josselyn explains the high soil salinity in the County parcel relative to AP and WP as due to groundwater derived salt being deposited in the soil via high evaporation. Although this mechanism certainly occurs in nature, I think a more parsimonious explanation is that the high salinity is an historical artifact of the period when the entire Parkside property was a tidal salt marsh. Diked salt marsh soils and dredge spoils placed in upland areas may retain their high salinity for many decades and the salinity in the upland soil on the County parcel is also very high. The lower (but still high) salinities in the agricultural field are probably a result of long-term agricultural manipulations. Next, Josselyn points out that the high rates of production and low rates of decomposition due to anaerobic conditions that are characteristic of wetlands result in an accumulation of organic matter. Although acknowledging that soil organics at AP and WP are similar to various reference wetlands, he suggests that the higher concentrations of organics on the County parcel are due to anaerobic conditions. However, confidence in wetland hydrology being the causative mechanism for the high organics is eroded by the fact that soil organics are actually higher in the upland than in the wetland within the County parcel. The patterns in ammonium and nitrate are perhaps most interesting, albeit somewhat confusing. In aerated soils with a pH above 4, nitrate is the most prevalent nitrogen compound and ammonium is generally in low


concentration39. The ratio is usually reversed in waterlogged soils due to the reduction of nitrate as described by Josselyn. In this context, the ammonium to nitrate ratio in the County parcel wetland, Los Patos wetland, and Banning Ranch salt marsh is in the direction expected in saturated soils and the ratio in the County parcel upland, WP, AP, and the Fairview freshwater wetland are in the direction expected for aerobic soils. However, if one looks at the ammonium concentrations, they are similar at all the locations except the Fairview wetland and perhaps WP. The most striking differences among the sites are the high levels of nitrate at the County upland, AP, and WP. Although the elevated levels of nitrate at AP and WP could possibly be related to agriculture, the high level40 at the County upland is puzzling. There is also considerable spatial variability within the County parcel. At sample sites 4-2 and 4-3, which bracket the area of interest between wells 8 and 9, the ammonium to nitrate ratios are 1.2 and 0.6, respectively. The corresponding figures for organic carbon are 1.2 and 0.8 and for pH are 6.4 and 6.8. In summary, the characteristics of the soil samples from AP and WP are similar to those of the hydrologically most appropriate reference area within the County parcel and are within the range of the other wetland sites sampled by Glenn Lukos. Conclusions The available data suggest that portions of the agricultural field at the Shea Homes Parkside site that have shown evidence of ponding in recent years are inundated or saturated at a frequency and duration sufficient to support a preponderance of wetland plant species, and that such a preponderance would exist if the current farming activity ceased. Such areas meet the definition of wetlands under the Coastal Act and the Commission’s Regulations.



California Coastal

Commission

This conclusion is based on two lines of evidence: (1) an examination of the vegetation at a nearby location that is similar in history, physical characteristics, and hydrology to the depressions in the agricultural field, and (2) an estimate of the frequency of continuous inundation for long duration (≥ 7 days). Areas WP and AP were matched with a wetland area on the County parcel that was similar (or higher) in elevation and topography. Inundation in the agricultural areas and at the reference wetland was similar in pattern and the vegetation in neither area appears to be supported by groundwater, further suggesting that the latter area is a good proxy for the former. Therefore, since the dominant vegetation at the reference areas is mostly comprised of wetland species, it is reasonable to expect that the agricultural areas WP and AP could also support a predominance of hydrophytes in the absence of farming. Whether the mix of wetland species that would eventually develop in the agricultural field would be similar to that observed on the County parcel is uncertain. Initially, the vegetation would probably be quite different, consisting mostly of annual species that are good colonizers, since the seed bank for perennial species has probably been destroyed due to the many years of farming. Over a period of decades, I would expect the vegetation in the two areas to become increasingly similar, although the lower salinity at WP and 39 Brix, H., K. dyhr-Jensen, and B. Lorenzen. 2002. Root-zone acidity and nitrogen source affects Typha latifolia L. growth and uptake kinetics of ammonium and nitrate. Journal of Experimental Botany 53:2442-2450. 40 One of the 3 samples is an outlier (145 ppm); the other 2 have 21 & 24 ppm nitrate with ammonium to nitrate ratios of 0.5.


especially AP might result in a different mix of species. However, the actual community trajectory and the rate of convergence in wetland cover would depend on many factors, especially whether rainfall during the first several years following the cessation of farming was heavy or light, initially favoring the establishment of wetland or upland species, respectively. The hydrology of the Shea Homes property has been significantly altered over the years. It was cut off from tidal influence long ago, but the freshwater surface hydrology has also been altered over the years by a reduction in the size of the watershed. Nevertheless, portions of the site probably have been continuously inundated for long duration at least once a year during about 60 percent of the last 47 years. Prior to about 1990, it appears from aerial photographs (Homrighausen 2005) that significant inundation was generally confined to the area delineated by the EPA (1989). Based on his analysis of aerial photographs dating from 1958 to 1985, Homrighausen (2005) concludes that inundation in that area tended to have a different footprint in different years and, based on this observation, he argues that no particular area should be identified as a wetland. However, all his estimated wetland polygons in the western portion of the agricultural field appear to fall within the area delineated by the EPA. In the absence of wetland vegetation, the drawing of wetland boundaries is an approximate exercise based on a small and haphazard collection of aerial photographs or ground observations and estimates of topography. Given the approximate nature of such delineations, I think Homrighausen’s (2005) results are actually additional evidence that the EPA delineation was both reasonable and accurate at the time it was made. From 1958 - 1985, inundation in the depression adjacent to the flood control channel apparently occurred less frequently than in the depression mapped by EPA. None of the investigators in the late 1980s delineated wetlands along the flood control channel, and Homrighausen (2005) found little evidence of ponding at WP prior to the 1980s. Yet, in recent years, there is ample evidence that WP is inundated for long duration following significant rainfall. In addition, ground photographs suggest that the area delineated by the EPA no longer ponds as frequently or as extensively as in earlier years. There appears to have been a state change in the hydrology of the site some time in the last 20 years or so. This change must be due to alterations in drainage patterns resulting from grading, plowing and disking by the agricultural tenants on the site.

EXHIBPa

IT#K ge 29 of 99


California Coastal

Commission

One could argue that the EPA delineation should stand because there has been no change in the overall hydrology of the site (i.e., total input and outflow of water) since 1989 and the recent photographic evidence is meager. Despite the paucity of data, I think the most defensible approach is to base the wetland delineation on current conditions as inferred from recent (2003)41 topography and the available photographs of recent inundation. I estimated the minimum boundary of wetlands in areas AP and WP based on 2003 topography and on the approximate area that each was inundated following a period of modest rainfall in a year of less than median rainfall. The wetland polygon in both area WP and area AP was based on the pattern of inundation during the period February 26 to March 6, 2004, which followed a storm that dropped 1.88

41 More recently a box plow was used to fill area WP, which is apparent in the 2006 topographic maps.


inches of rain during a relatively dry year (5.8” total rainfall). A large area at WP was continuously inundated (Figure 6). The wetland polygon at AP was based on the area inundated on February 26 (Figure 7). By March 6, the area was probably smaller, but the available photograph shows only a small portion of the area shown in the February photograph. Unfortunately, there are few photographs of the AP area, except during periods of exceptionally heavy rainfall (e.g., Figure 3). The actual boundary of the wetland polygons (Figure 8) was obtained by following the contour that seemed to approximate the area that was observed to pond following rainfall. For AP this was the 0-foot contour42; for WP this was about the 1.2-foot contour. Given the small amount of rainfall during this period, I think the area delineated is reasonable and possibly conservative. The areas of ponding resulting from high groundwater in 2006 all appear to have been within the delineated AP area. Although the areas delineated in Figure 8 represent the minimum areas that are likely to support wetland vegetation in the absence of farming, even these small areas would probably lose their wetland character if the amount of water from rainfall and local runoff were to be reduced. Therefore, if they are to persist in the absence of farming, either their watershed must be maintained or supplemental water must be provided.



California Coastal

Commission

42 Relative to NAVD88 vertical datum.


Figure 1. Shea Homes property at Bolsa Chica in Huntington Beach. Portions of the property were previously within the unincorporated area of the County of Orange. In the text there is reference to the “City Parcel” and the “County Parcel,” although the latter was annexed by the City in 2003.



California Coastal

Commission


Figure 2. Wetland area delineated by Bilhorn (1987). The wetland polygon shown in Bilhorn’s map was scanned and then positioned on the recent aerial photograph using ArcView. The size, shape and position of the polygon is approximate. The wetland area calculated from the mapped polygon is 7.6 acres, which is the same area estimated by Bilhorn (1987).



California Coastal

Commission


Figure 3. Large portions of the Shea Homes property were continuously inundated for over 30 days during the unusually wet winter of 2000 - 2001. Area AP is in the foreground; area WP is in the background adjacent to the flood control channel. Photographs from Bixby (2005).



California Coastal

Commission


Figure 4. Former County parcel after wetlands had been disturbed by agricultural activities and fill in 1997 and 1998 (staff photographs). Upper photograph - 10/22/98; lower photograph - 12/05/98. Note palm tree that is also shown in Figure 5.



California Coastal

Commission


Figure 5. Former County parcel on 02/26/04 showing developing vegetation following the cessation of agricultural disturbance. Based on observations by Harrison (2000), LSA (2002), Bomkamp et al. (2005) and Fontaine (2005a), a variety of wetland species are becoming established and the area with a preponderance of hydrophytes is increasing. The area with standing water typically ponds following significant rainfall. The palm tree and tire ruts created by driving over wet ground provide references when analyzing inundation from a temporal series of photographs. Photograph from Bixby (2005).



California Coastal

Commission


Figure 6. Ponding in area WP during February and March, 2004. Photographs from Bixby (2005).

February 26, 2004

March 6, 2004

March 11, 2004



California Coastal

Commission


Figure 7. Ponding in area AP during February and March, 2004 following 1.88 inches of rain on February 26 and an additional 0.52 inches on March 2. The March photograph includes only a small portion of the area shown in the February photograph. Photographs from Bixby (2005).

March 6, 2004

February 26, 2004



California Coastal

Commission


Figure 8. Estimated size and location of wetland areas that currently would support a preponderance of wetland plant species in the absence of agriculture. A 100-foot wetland buffer is shown in black.



California Coastal

Commission


Figure 9. Map of the County parcel (CP) showing the location of monitoring wells and sampling plots for vegetation and soils.



California Coastal

Commission


Figure 10. Map of area AP along the western edge of the agricultural field showing the location of monitoring wells and sampling plots for vegetation and soils.



California Coastal

Commission


Figure 11. Map of area WP adjacent to the flood control channel within the agricultural field showing the location of monitoring wells and sampling plots for vegetation and soils.



California Coastal

Commission


Table 1. Summary of occurrences of long duration ponding at areas WP and AP as assessed from aerial and ground-level photographs and from rainfall data during the period 1985 – 2005. Y = Yes; N=No.

Evidence of Ponding From Photographs Rainfall Year

WP AP

Inferred From

Rainfall

Estimated Duration of Ponding at WP

2004 - 2005 Y Y Y > 30 days 2003 - 2004 Y N Y* 7 - 14 days 2002 - 2003 Y N Y 7 - 14 days 2001 – 2002 N N N < 7 days 2000 – 2001 Y Y Y > 30 days 1999 – 2000 N N N < 7 days 1998 – 1999 N N N < 7 days 1997 – 1998 Y Y Y > 30 days 1996 - 1997 Y Y Y 15 - 30 days 1995 - 1996 N N Y 7 - 14 days 1994 - 1995 Y Y Y > 30 days 1993 - 1994 N N N < 7 days 1992 - 1993 Y Y Y > 30 days 1991 - 1992 Y N Y 15 - 30 days 1990 - 1991 N N Y 7 - 14 days 1989 - 1990 N N N < 7 days 1988 - 1989 N N N < 7 days 1987 - 1988 N N N < 7 days 1986 - 1987 N N N < 7 days 1985 - 1986 Y Y Y 15 - 30days

* WP only



California Coastal

Commission


Table 2. Summary of occurrences of long duration ponding at areas WP and AP as assessed from aerial photographs and from rainfall data during the period 1958 – 1985. Where the photographic analysis suggested inundation but LSA considered it a “false positive,” I entered “N” in columns 3 and 4. An asterisk in column 4 indicates that LSA concluded that ponding was less than 14 days. Y = Yes; N = No. LSA estimated that ponding for more than 14 days occurred at AP during 13 years and at WP during 5 years over the 27-year period of record (Appendix B, Table B28#).

Evidence of Ponding From Photographs Rainfall Year

WP AP

Ponding Inferred

From Rainfall

Estimated Duration of Ponding at AP

1984 - 1985 N N Y* 15 - 30 days 1983 - 1984 N N N < 7 days 1982 - 1983 N N Y > 30 days 1981 - 1982 N N N < 7 days 1980 - 1981# Y Y Y 15 - 30 days 1979 - 1980 N Y Y > 30 days 1978 - 1979 N N Y 15 - 30 days 1977 - 1978 - - Y > 30 days 1976 - 1977 N N N < 7 days 1975 - 1976 N N N < 7 days 1974 - 1975 Y Y Y* 7 - 14 days 1973 - 1974 N N Y 7 - 14 days 1972 - 1973 N N Y* 7 - 14 days 1971 - 1972 N N Y* 7 - 14 days 1970 - 1971 N N Y 7 - 14 days 1969 - 1970 N N N < 7 days 1968 - 1969 - - Y > 30 days 1967 - 1968 - - N < 7 days 1966 - 1967 - - Y 7 - 14 days 1965 - 1966 - - Y 15 - 30 days 1964 - 1965 N Y Y 7 - 14 days 1963 - 1964 - - N < 7 days 1962 - 1963 N Y Y 7 - 14 days 1961 - 1962 N Y Y 15 - 30 days 1960 - 1961 - - N < 7 days 1959 - 1960 N N Y* 7 - 14 days 1958 - 1959 N N N < 7 days

# Data for 1980-1981 correspond to Appendix B, Table B23; entry in Table B28 is apparently wrong.



California Coastal

Commission


Table 3. Number of years during which there was continuous ponding for long duration relative to the total amount of rainfall during the rain year (July - June). Y = ≥ 7 days continuous ponding; N = 0-6 days continuous ponding. Median annual rainfall for the 47-year period from 1958 through 2005 was 9.0 inches (Quartile43 1 = 6.5”; Quartile 3 = 12.3”). The shaded area delineates rain years with median rainfall or less. During 1958 - 1985, ponding figures are for area AP; during 1985 - 2005, ponding figures are for area WP. The depression at area WP may not have been present during much of the earlier period. After around 1985, area AP probably generally ponded at the same time as area WP

1958 - 1985 1985 - 2005 1958 - 2005 Total Amount of Rainfall (in) Y N Y N Y N

0-2 0 0 0 0 0 0 2-4 0 1 0 1 0 2 4-6 1 3 1 3 2 6 6-8 3 4 1 3 4 7

8-9.0 0 0 1 1 1 1 9.1-10 5 1 0 0 5 1 10-12 2 0 3 0 5 0 12-14 3 0 2 0 5 0 14-16 0 0 0 0 0 0 16-18 3 0 0 0 3 0 18-20 0 0 2 0 2 0 20-22 1 0 1 0 2 0 22-24 0 0 1 0 1 0 Total: 18 9 12 8 30 17



California Coastal

Commission

43 Quartile 1 is the upper bound of the lowest 25% of observations and Quartile 3 is the lower bound of the highest 25% of observations.


Table 4. Relationship between the duration of ponding and the total amount of rainfall during the rain year (July - June). Entries are number of years within each category during the period 1958 - 2005. Median annual rainfall for the 47-year period from 1958 through 2005 was 9.0 inches (Quartile 1 = 6.5”; Quartile 3 = 12.3”). The shaded area delineates rain years with median rainfall or less. During 1958 - 1985, ponding figures are for area AP; during 1985 - 2005, ponding figures are for area WP. The depression at area WP may not have been present during much of the earlier period. After around 1985, area AP probably generally ponded at the same time as area WP.

Estimated Duration of Continuous Ponding Total Amount of Rainfall (in) 0 - 6

days 7 - 14 days

15 - 30 days

> 30 days

0-2 0 0 0 0 2-4 2 0 0 0 4-6 6 2 0 0 6-8 7 3 1 0

8-9.0 1 1 0 0 9.1 - 10 1 4 1 0

10-12 0 1 4 0 12-14 0 2 2 1 14-16 0 0 0 0 16-18 0 0 0 3 18-20 0 0 0 2 20-22 0 0 0 2 22-24 0 0 0 1 Total: 17 13 8 9



California Coastal

Commission


Table 5. Water depth below the surface at the LSA monitoring wells in the former County parcel during winters 1999-2000 and 2001-2002. Where the water table is within the upper 1 foot of the soil column, the depth is indicated in bold type.

Station: LSA 6 LSA 8 LSA 9 LSA 10

LSA 12

LSA 13

LSA 14

LSA 15

LSA 16

Cumulative Rainfall During Prior 7 Days

Cumulative Rainfall During Prior 30

Days Station

Elevation (MSL):

3.3 ft 1.3 ft 0.9 ft 1.3 ft 0.8 ft 1.0 ft -0.1 ft -0.4 ft -0.2 ft

12/17/1999 -3.95 -2.35 -4.90 -1.80 -3.05 -3.25 0.00 0.00 12/30/1999 -4.10 -2.45 -2.90 -1.90 -3.20 -3.35 0.00 0.00 1/5/2000 -4.05 -2.40 -4.00 -1.90 -3.05 -3.30 0.07 0.07 1/20/2000 -4.10 -2.45 -3.95 -2.00 -3.10 -3.30 0.00 0.07 1/26/2000 -3.85 -1.90 -3.75 -1.40 -2.55 -4.90 -2.90 0.51 0.58 2/1/2000 -3.90 -2.05 -3.70 -1.50 -2.70 -4.90 -2.80 0.41 0.62 2/18/2000 -3.15 -0.90 -3.00 -0.40 -1.95 -4.25 -2.10 0.85 1.87 2/25/2000 -4.95 0.00 -0.40 -1.35 0.00 -0.40 -1.20 -0.60 1.95 3.31 3/3/2000 -2.45 -1.00 -2.15 0.00 -1.20 -2.45 -1.35 0.06 3.26 3/10/2000 -4.35 -0.10 -0.80 -1.40 -0.25 -0.40 -1.00 -0.75 1.33 4.59 3/17/2000 -4.65 -2.40 -1.15 -2.10 -0.50 -1.20 -2.10 -1.30 0.00 3.62 3/24/2000 -4.90 -2.60 -1.55 -2.35 -0.95 -1.55 -2.60 -1.60 0.00 1.82 3/31/2000 -4.90 -2.60 -1.05 -2.35 -0.45 -1.55 -2.90 -1.65 0.00 1.33 4/7/2000 -2.85 -1.75 -2.65 -1.15 -1.90 -3.15 -1.95 0.00 0.05 4/20/2000 -4.85 -2.55 -1.30 -2.30 -0.60 -1.50 -2.85 -1.65 0.81 0.81 5/3/2000 -2.95 -1.65 -2.75 -1.10 -2.00 -3.50 -2.10 0.00 0.81 12/21/2001 -5.25 -5.45 -3.25 -0.70 -3.15 -0.30 -2.20 -4.70 -2.55 0.08 1.00 12/31/2001 -5.15 -5.25 -2.90 -0.65 -2.80 -0.25 -1.70 -4.60 -2.05 0.32 0.94 1/14/2002 -5.30 -5.45 -3.55 -1.40 -3.35 -0.70 -2.35 -4.75 -2.65 0.00 0.64 1/28/2002 -5.30 -5.50 -3.45 -1.10 -3.30 -0.55 -2.30 -4.80 -2.50 0.00 0.72 1/31/2002 -5.30 -5.55 -3.60 -1.50 -3.40 -1.10 -2.45 -4.85 -2.75 0.29 0.29 2/15/2002 -5.30 -3.70 -1.75 -3.50 -1.15 -2.60 -4.90 -2.60 0.00 0.29 2/18/2002 -5.20 -3.30 -1.40 -3.20 -0.80 -2.15 -4.80 -2.50 0.16 0.57 3/4/2002 -5.15 -3.60 -1.85 -3.35 -1.30 -2.55 -4.75 -2.70 0.00 0.28 3/11/2002 -5.15 -5.45 -3.40 -1.50 -3.25 -0.85 -2.34 -4.70 -2.60 0.04 0.32 3/19/2002 -5.15 -3.55 -1.80 -3.35 -1.15 -2.40 -4.75 -2.70 0.13 0.29 3/27/2002 -5.20 -3.50 -1.55 -3.30 -1.00 -2.40 -4.70 -2.55 0.05 0.22



California Coastal

Commission


Table 6. Correlation (r) between cumulative rainfall prior to the date of the observation and the change in the water depth below the surface (WDBS) since the previous observation. Observations were generally made on weekly or biweekly intervals. Statistically significant (p ≤ 0.05) correlations in bold. The proportion of the variability in water depth explained by rainfall (r2) in parentheses.

Station WDBS vs 7-Day Cumulative Rainfall

WDBS vs 30-Day Cumulative Rainfall

LSA 6 0.508 0.221 LSA 8 0.174 -0.325 LSA 9 0.787 (.62) 0.156 LSA 10 0.510 (.26) 0.115 LSA 12 0.588 (.35) 0.120 LSA13 0.390 (.15) 0.097 LSA 14 0.822 (.68) 0.209 LSA 15 0.897 (.80) 0.282 LSA 16 0.823 (.68) 0.213



California Coastal

Commission


Table 7. Water depth below the surface at Pacific Soil’s monitoring wells. Where the water table is within the upper 12 inces of the soil column, the depth is indicated in bold type. PS-7 and PS-8 are next to the flood control channel at each end of WP, PS-12 is next to the flood control channel at the County parcel (CP), and PS 16 is on the slope above AP. Data for the 2005-2006 rain year are anomalous due to the lagged effects of the extraordinarily high precipitation of the previous year and are not included.

Date PS-7 (Elev=1.7 ft) PS-8 (Elev=1.3 ft) PS-12 (Elev=1.8 ft) PS-16 (Elev=3.4 ft) 12/1/1999 4.61 7.10 4.51 10.50 12/2/1999 4.68 5.32 2.87 10.50 12/8/1999 4.68 5.35 2.88 10.50

12/22/1999 4.55 3.59 2.67 10.50 1/25/2000 4.43 3.26 2.56 10.50 3/3/2000 2.88 1.21 0.21 10.22

3/31/2000 3.72 1.86 1.06 10.20 5/26/2000 3.27 2.53 1.81 10.50 7/19/2000 3.94 2.77 2.48 10.50 8/21/2000 4.07 2.38 2.37 10.30 9/29/2000 4.00 2.19 1.91 10.50

10/16/2000 4.04 2.29 2.47 11/27/2000 4.18 2.10 2.22 12/31/2000 4.10 2.18 2.17 1/30/2001 3.61 1.84 2.08 3/16/2001 2.05 1.43 1.18 5/11/2001 3.35 2.22 1.18 2/8/2002 2.90 3.08 1.69

10/18/2002 3.79 2.21 1/24/2003 3.67 2.04 3/11/2003 2.69 3/14/2003 8.42 4/4/2003 5.71 1.31

5/23/2003 2.80 1.78 7/25/2003 2.15 2.16

10/31/2004 2.06 2/20/2004 1.78 6/11/2004 1.64 8/9/2004 1.76



California Coastal

Commission


Table 8. Soil characteristics at potential wetlands within the agricultural field (AP and WP) and at various reference wetlands. CP is the former County parcel. The Upland samples were taken a few feet outside the area of wetland vegetation.

Variate Descriptive Statistic

CP Upland (n=3)

CP Wetland (n=25)

AP (n=9)

WP (n=9)

Los Patos Seasonal

Freshwater Wetland

(n=2)

Fairview Seasonal

Freshwater Wetland

(n=3)

Banning Ranch

Salt Marsh (n=3)

Mean 23.8 28.3 21.0 35.8 30.0 44.8 32.7 Clay (%) SE 1.0 2.1 1.9 1.0 4.0 1.5 1.9

Mean 5.4 5.7 7.0 7.5 7.1 6.4 7.1 pH

SE 0.2 0.2 0.1 0.0 0.2 0.1 0.1

Mean 11.3 14.9 12.8 4.4 11.0 0.9 8.3 NH4 (ppm) SE 0.3 2.8 3.3 1.0 3.0 0.1 0.3

Mean 63.3 7.1 41.8 24.7 4.0 10.3 5.7 NO3 (ppm) SE 40.1 0.8 25.6 4.2 2.0 1.3 1.8

Mean 0.4 2.1 0.7 0.3 3.2 0.9 1.8 NH4/NO3

SE 0.1 0.2 0.2 0.1 0.8 0.1 0.5

Mean 9.5 7.1 5.8 1.0 0.7 1.7 2.0 Total Organics

(% dry wt) SE 0.9 0.8 0.8 0.1 0.3 0.2 0.2

Mean 5.4 4.0 3.2 0.5 0.4 1.0 1.1 TOC (%) SE 0.5 0.4 0.4 0.2 0.1 0.1 0.1

Mean 20.4 38.7 30.4 13.6 5.3 2.8 35.1 SAR

SE 0.0 2.9 2.9 0.5 1.2 0.1 7.7

Mean 24.9 40.6 4.4 11.4 1.9 0.7 29.0 ECe (dS/m) SE 2.6 3.5 0.4 1.0 0.1 0.0 6.1

Mean 50.2 76.0 30.4 38.0 5.3 2.3 50.0 SO4 (me/l) SE 4.9 3.6 2.9 3.0 0.2 0.4 2.6

Mean 810 787 225 31 79 89 160 Fe (ppm) SE 84 128 35 2 12 11 54



California Coastal

Commission


APPENDIX A.

Tables A1 – A20: Photographic evidence of ponding (=flooding), and rainfall data for the period 1985 – 2000. All rainfall data from Los Alamitos Station (Number 170). There was no rainfall on dates not tabulated during the period October - March of each year. “Long duration” is defined as, “A flooding class in which the period of inundation for a single event ranges from 7 days to 1 month.” “Very long duration” is defined as, “A duration class in which the length of a single inundation event is greater than 1 month.”44



California Coastal

Commission

44 Environmental Laboratory. 1987. Corps of Engineers Wetlands Delineation Manual. Technical Report Y-87-1, U.S. Army Engineer Waterways Experiment Stations, Vicksburg, Mississippi.


Table A1. Rainfall and inundation during the 2004-2005 Season. Inundation data from ground-level photographs (Bixby 2005). Extensive areas of WP and AP were continuously ponded during most of the winter (shaded periods). Based on the photographs and on the rainfall pattern and amount, it is likely that both WP and AP were continuously inundated for more than 30 days during the shaded period.

Date Rainfall Former County Parcel “Pickleweed/Sea Blite Scrub” Wetland (LSA)

South-Central Depression at Channel

Berm (WP)

Western Depression (AP)

10/01/04 – 10/16/04

0.0 - - -

10/17/04 2.46 Modest Pond (c. 15’ x 25’)

Large pond in field (c. 40’ x 120’; probably equal area to E out of photo)

Long linear pond in field (c. 25’ x 200’)

10/18/04 0.12 10/19/04 0.0 Standing water only in

ruts Large pond in field Pond much reduced (c.

15’ x 20’) 10/20/04 1.88 - - - 10/21/04 0.31 Modest Pond

Large pond in field Large linear pond in field

(c. 25’ x 200’) 10/22/04 0.0 - - - 10/23/04 0.0 Modest Pond Large pond in field Large linear pond in field

(c. 15’ x 100’) 10/24/04 – 10/25/06

0.0 - - -

10/26/04 0.0 Pond nearly gone Large pond in field Pond much reduced (c. 15’ x 20’)

10/27/04 1.77 Larger pond (c. 15’ x 45’)

Large pond in field Large linear pond in field (c. 40’ x 250’)

10/28/04 0.20 - - - 10/29/04 0.0 - - - 10/30/04 Modest pond Large pond in field Large linear pond in field

(c. 25’ x 100’) 10/31/04 0.0 - - - 11/01/04 0.0 - - - 11/02/04 0.0 No standing water Large pond in field Pond much reduced (c.

25’ x 20’) 11/03/04 – 11/30/04

0.43 - - -

DEC 2.52 - - - JAN 5.21 FEB 7.35 MAR 0.51

Periodically ponded, sometimes extensively

Continuously extensively ponded

Continously ponded, generally extensively



California Coastal

Commission


Table A2. Rainfall and inundation during the 2003-2004 season. Shaded rainfall considered “near normal” for January or February. Inundation data from ground-level photographs (Bixby 2005). Shaded period is evidence of long duration inundation during near normal rainfall. Based the photographs, it is likely that WP was continuously inundated for 7 - 14 days during the shaded period. AP may have been ponded for fewer than 7 days. .

EXHIBIT#K ge 52 of 99 Pa


California Coastal

Commission

Date Rainfall

Former County Parcel “Pickleweed/Sea Blite Scrub” Wetland (LSA)

South-Central Depression at Channel Berm (WP)


OCT 0 - - - NOV 0.68 - - - 12/01/03 – 12/25/03

0.32 - - -

12/26/03 0.42 Modest Pond Ponded or wet on road; little or no ponding in field

Ponded in furrows near bend in road

12/28/03 0 Pond reduced to ruts Ponded or wet on road; little or no ponding in field


12/30/03 0 Pond reduced to ruts 12/31/03 0 Ponded or wet on road; little or no

ponding in field No standing water

01/01/04 0 No surface water Ponded or wet on road; little or no ponding in field

No standing water

01/03/04 0.34 Modest pond Ponded or wet on road; little or no ponding in field


01/10/04 0 No surface water Ponded or wet on road; little or no ponding in field

No standing water

01/19/04 0.01 - - - 02/03/04 0.58 Modest pond Ponded or wet on road; little or no

ponding in field Ponded in furrows near bend in road

02/07/04 0 No standing water Ponded or wet on road; little or no ponding in field


02/08/04 0 Muddy and glistening at surface

Ponded or wet on road; little or no ponding in field

Less extensive ponding

02/09/04 0 No standing water; not glistening at surface

Ponded or wet on road; little or no ponding in field

Less extensive ponding

02/13/04 0 - - - 02/19/04 0.26 Ponded mostly in ruts Ponded or wet on road; little or no

ponding in field Very shallow surface water

02/22/04 0.31 Modest pond - - 02/23/04 0.18 Pond reduced Ponded or wet on road; little or no

ponding in field No standing water

02/26/04 1.88 Modest pond Extensive ponding in furrows in field Large pond

02/28/04 0 Pond reduced Extensive ponding in furrows in field Pond reduced in size 03/01/04 0 Ponded in ruts Extensive ponding in furrows in field Appears saturated to

surface, but not inundated 03/02/04 0.52 Ponded in ruts and

depressions Extensive ponding in furrows in field Ponded in furrows

03/04/04 0 Ponded in ruts Extensive ponding in furrows in field Ponded in furrows but less extensive

03/06/04 0 Ponded in ruts Extensive ponding in furrows in field Ponded in furrows but less extensive

03/11/04 - Minor ponding in furrows in field - 03/13/04 0 - Field is muddy & glistening at surface -


Table A3. Rainfall and inundation during the 2002-2003 season. Inundation data from ground-level photographs (Bixby 2005). Shaded period is evidence of long duration inundation during near normal rainfall. Based on the photographs, it is likely that both WP and AP were continuously inundated for 7 - 14 days during the shaded period..

HIBIT#K ge 53 of 99

EXPa


California Coastal

Commission


South-Central Depression at Channel Berm (WP) Western Depression (AP)

OCT 0.11 - - - 11/08/02 - 11/10/02 1.07 - -- -

11/30/02 0.54 - - -

12/17/02 1.03 Pond (c. 12’ x 15’) Recently plowed. Ponded on (plowed) road and adjacent furrows in area c. 15’ x 30’.

Ponded in field at bend (c. 20’ x 50’)

12/18/02 0.21

12/19/02 0 Pond (c. 15’ x 20’) Mostly wet on surface; standing water in furrows

12/20/02 0.62 Pond (c. 20’ x 30’) Large area (c. 60’ x 120’) ponded in furrows within field

Ponded in field at bend & toward Eucalyptus (c. 40’ x 150’)

12/21/02 0.06 Pond (c. 20’ x 30’) Large area (c. 60’ x 120’) ponded in furrows within field

Ponded in field at bend & toward Eucalyptus (c. 40’ x 150’)

12/22/02 0 Pond (c. 15’ x 20’) Large area (c. 60’ x 120’) ponded in furrows within field

Ponded in field at bend & toward Eucalyptus (c. 40’ x 150’); shallow water or glistening at surface

12/23/02 0 - Inundated area appears much reduced in poor photo

Shallow standing water or glistening at surface in small area (c. 15’ x 20’) at bend.

12/24/02 0 Pond (c. 12’ x 15’)

Inundated area appears much reduced in poor photo; muddy and glistening at the surface in some areas

-

12/27/02 0 Shallow standing water mostly in ruts Wet at surface; little standing water No standing water

12/28/02 0 Muddy & glistening at surface; water in ruts

Muddy and glistening at the surface; standing water in furrows Muddy & glistening at surface

12/29/02 0.08 Pond (c. 12’ x 15’) Small patch with standing water in furrows

Muddy & glistening at surface; standing water in furrows

JAN 0.00

01/04/03 0 - - Muddy & glistening at surface; standing water in furrows

02/01/03 - 02/10/03 0.00

02/11/03 - 01/14/03 2.62

02/15/03 - 02/24/03 0.00

02/25/03 - 02/28/03 1.16

03/04/03 0.15 - - - 03/15/03 - 03/16/03 3.19 - - -

03/20/03 0 - Road nearly dry -


Table A4. Rainfall and inundation during the 2001-2002 season. Inundation data from vertical aerial photograph (Homrighausen 2005). Based on rainfall pattern and amount, it is unlikely that WP or AP were continuously inundated for long duration during this season.




OCT 0.00 - - - NOV 0.89 - - - DEC 0.94 - - - JAN 0.29 - - - FEB 0.28 - - - MAR 0.22 - - - APR 0.20 - - - 05/01/02 – 05/22/02

0.05 - - -

05/23/02 0.00 No ponds visible No ponds visible No ponds visible



California Coastal

Commission


Table A5. Rainfall and inundation during the 2000-2001 season. Inundation data from ground-level photographs (Bixby 2005). Lightly shaded period is evidence of long duration inundation during near normal rainfall. Based on rainfall pattern and amount, it is likely that WP and AP were continuously inundated for more than 30 days during February and March (dark shaded period).




OCT 2.71 - - - NOV 0.01 - - - DEC 0 - - - 01/01/01 – 01/08/01

0.00 - - -

01/09/01 – 1/13/01

2.47 - - -

01/14/01 – 01/23/01

0 - - -

01/24/01 0.12 - - - 01/25/01 0.29 - - - 01/26/01 0.21 - - - 01/27/01 0.32 - - - 01/28/01 – 01/30/01

0 - - -

01/31/01 0 No photographs available. Road and large portion (c. 150’ x 200’) of adjacent field ponded

No photographs available.

02/01/01 – 02/09/01

0.00 - - -

02/10/01 – 02/14.01

2.67 - - -

02/15/01 – 02/19/01

0 - - -

02/20/01 – 02/28/01

3.62 - - -

03/01/01 0.14 - - - 03/06/01 0.46 - - - 03/07/01 0.07 - - - 03/10/01 0.13 - - - 03/12/01 0 No photographs available. Large portion of field ponded Very large area (c. 200 x

700’) ponded 03/14/01 0 No photographs available. Large portion of field ponded Very large area (c. 200 x

700’) ponded 03/18/01 0 No photographs available. No photographs available. Very large area (c. 200 x

700’) ponded 03/23/01 0 No photographs available. No photographs available. Very large area (c. 200 x

700’) ponded 03/28/01 0 No photographs available. No photographs available. Previously ponded area

appears to be mud with scattered ponds



California Coastal

Commission


Table A6. Rainfall and inundation during the 1999-2000 season. Inundation data from ground-level photographs (Bixby 2005). Based on rainfall pattern and amount, it is unlikely that WP or AP were continuously inundated for long duration during this season.




OCT 0.00 - - - NOV 0.18 - - - DEC 0.00 - - - JAN 0.69 - - - 02/01/00 0.00 - - - 02/02/00 0.00 No ponds visible No ponds visible No ponds visible 02/03/00 – 02/10/00

0.00 - - -

02/11/00 0.40 02/12/00 0.35 02/13/00 0.00 02/14/00 0.16 02/15/00 0.00 02/16/00 0.06 02/17/00 0.28 02/18/00 – 02/19/00

0.00

02/20/00 0.15 02/21/00 0.79 02/22/00 0.46 - - - 02/23/00 0.12 - - - 02/24/00 0.43 02/25/00 – 02/27/00

0.00

02/28/00 0.06 03/01/00 – 03/03/00

0.00 - - -

03/04/00 – 03/09/00

1.33 - - -

03/09/00 – 03/31/00

0.00 - - -



California Coastal

Commission


Table A7. Rainfall and inundation during the 1998-1999 season. Inundation data from vertical aerial photograph (Homrighausen 2005). Based on rainfall pattern and amount, it is unlikely that WP or AP were continuously inundated for long duration during this season.




OCT 0.15 - - - NOV 0.77 - - - DEC 0.78 - - - 01/01/99 – 01/04/99

0.00 - - -

01/05/99 0.00 No ponds visible No ponds visible No ponds visible 01/06/99 – 01/19/99

0.00 - - -

01/20/99 – 01/31/99

1.09 - - -

FEB 0.79 - - - MAR 1.37 - - -



California Coastal

Commission


Table A8. Rainfall and inundation during the 1997 – 1998 season. Inundation data from ground-level photographs (Bixby 2005). Lightly shaded period is evidence of long duration inundation during near normal rainfall. Based on rainfall pattern and amount, it is likely that WP and AP were continuously inundated for more than 30 days during this winter season (light and dark shaded periods).



California Coastal

Commission




OCT 0 - - - 11/11/97 – 11/14/97

0.97 - - -

11/15/97 – 11/26/97

0 - - -

11/27/97 0.62 - - - 12/01/97 0.37 - - - 12/06/97 1.88 - - - 12/07/97 0.23 Large ponded area. Too

distant in photograph to estimate size.

Road and large area (c. 150’ x 250’) in field ponded

No photographs available for this year

12/09/97 0.08 - - 12/13/97 0 - Ponding much reduced but still

extensive areas of standing water within muddy field

-

12/18/97 0 - Ponding much reduced but still extensive areas of standing water within muddy field

-

12/19/97 1.14 - - - 12/20/97 0 Large ponded area - - 12/21/97 0.28 - - - 12/22/97 0 - Large ponds among furrows - 01/05/98 0.11 - - 01/06/98 0 - Many scattered large ponds - 01/09/98 – 01/11/98

0.85 - - -

01/12/98 0 Large ponded area Large portions of field ponded within larger muddy area

-

01/13/98 0.09 - - - 01/14/98 0 - Large portions of field ponded

within larger muddy area -

01/15/98 0 Pond present - - 01/17/98 0 Pond present - - 01/18/98 0 Large portions of field ponded

within larger muddy area -

01/19/98 0.14 Pond present - 01/21/98 0 Scattered areas of

standing water in muddy area

Large portions of field ponded within larger muddy area

-

1/30/98 – 1/31/98

0.51 - - -

FEB 8.56 Large pond on Feb 7; whole parcel appears inundated on Feb 12, 16, 19, & 26

Very large pond on Feb 1,5,10,16,19 & 26

-

MAR 2.51 - Large pond on Mar 29 -


Table A9. Rainfall and inundation during the 1996 – 1997 season. Inundation data from oblique aerial photograph (Bixby 2005) and vertical aerial photograph (Homrighausen 2005). Based on the photographs and on rainfall pattern and amount, it is likely that WP and AP were continuously inundated for 15 - 30 days during the shaded period in January.



California Coastal

Commission




OCT 0.77 - - - 11/01/96 – 11/20/96

0.00 - - -

11/21/96 – 11/22/96

2.00 - - -

11/23/96 – 11/30/96

0.00 - - -

12/01/96 – 12/09/96

0.16 - - -

12/10/96 – 12/12/96

2.22 - - -

12/13/96 – 12/22/96

0.00 - - -

12/23/96 0.16 - - - 12/24/96 – 12/27/96

0.00 - - -

12/28/81 0.42 - - - 12/29/96 – 12/31/96

0.00 - - -

01/01/97 – 01/03/97

0.43 - - -

01/04/97 – 01/05/97

0.00 - - -

01/06/97 0.12 - - - 01/07/97 – 01/12/97

0.00 - - -

01/13/97 1.65 - - - 01/14/97 – 01/15/97

0.00 - - -

01/16/97 0.85 - - - 01/22/97 0.51 - - - 01/23/97 0.38 - - - 01/24/97 – 01/25/97

0.00 - - -

01/26/97 0.81 - - - 01/27/97 – 01/28/79

0.00 - - -

01/29/97 0.00 Large pond in oblique aerial photograph in vicinity of palm tree

Entire WP area inundated Not visible in photograph

02/01/97 – 02/13/97

0.12 - - -

02/14/97 0.00 - Ponded Not Ponded 02/15/97 – 02/28/97

0.00

MAR 0.00 - - -


Table A10. Rainfall and inundation during the 1995-1996 season. Inundation data from vertical aerial photograph (Homrighausen 2005). Based on rainfall pattern and amount, it is likely that WP and perhaps AP were continuously inundated for 7 - 14 days during the shaded period in February.




OCT 0.00 - - - NOV 0.04 - - - 12/01/95 – 12/14/95

0.69 - - -

12/15/95 – 12/22/95

0.00 - - -

12/23/95 – 12/24/95

0.59

12/25/95 – 12/31/95

0.00 - - -

01/01/96 – 01/10/96

0.00 - - -

01/11/96 0.00 No ponds visible No ponds visible No ponds visible 01/12/96 - 01/16/96

0.0

01/17/96 - 01/22/96

0.82

01/28/96 - 01/31/96

0.48

02/01/96 – 02/04/96

0.54 - - -

02/05/96 – 02/19/96

0.00 - - -

02/20/96 – 02/22/96

2.09 - - -

02/23/96 – 02/24/96

0.00 - - -

02/25/96 – 02/28/96

0.61 - - -

02/29/96 0.00 - - - 03/01/96 – 03/04/96

0.00 - - -

03/05/96 0.71 - - - 03/06/96 – 03/12/96

0.00 - - -

03/13/96 0.27 - - - 03/14/96 – 03/31/96

0.00 - - -



California Coastal

Commission


Table A11. Rainfall and inundation during the 1994-1995 season. Inundation data from a vertical aerial photograph (Homrighausen 2005). Based on the photographs and on rainfall pattern and amount, it is likely that WP and AP were continuously inundated for more than 30 days during the shaded period in January and in early February.

IBIT#K Page 61 of 99

EXH


California Coastal

Commission




OCT 0.11 - - - NOV 0.47 - - - DEC 0.85 - - - 01/01/95 – 01/02/95

0.00 - - -

01/03/95 – 01/05/95

5.32 - - -

01/06/95 0.00 - - - 01/07/95 – 01/12/95

4.01 - - -

01/13/95 – 01/15/95

0.00 - - -

01/16/95 0.11 - - - 01/17/95 – 01/20/95

0.00 - - -

01/21/95 0.30 - - - 01/22/95 – 01/23/95

0.00 - - -

01/24/95 – 01/26/95

1.99 - - -

01/27/95 0.00 - - - 01/28/95 0.00 Not Analyzed* Ponded Ponded 01/29/95 – 01/31/95

0.00 - - -

FEB 0.45 - - - 03/01/95 – 03/05/95

0.00 - - -

03/06/95 1.40 - - - 03/07/95 – 03/10/95

0.00 - - -

03/11/95 – 03/12/95

1.72 - - -

03/13/95 – 03/20/95

0.00 - - -

03/21/95 – 03/22/95

0.78 - - -

03/23/95 – 03/26/95

0.00 - - -

03/27/95 0.00 Not Analyzed* Ponded Ponded 03/28/95 – 03/31/95

0.00 - - -

- - - * LSA did not analyse this portion of the photograph; M.Bixby (2005) interpreted the photographs to

show ponding in the County area.


Table A12. Rainfall and inundation during the 1993-1994 season. Inundation data from a vertical aerial photograph (Homrighausen 2005). Based on rainfall pattern and amount, it is unlikely that WP or AP were continuously inundated for long duration during this season.

Date Rainfall Former County Parcel

“Pickleweed/Sea Blite Scrub” Wetland (LSA)



OCT 0.04 - - - NOV 0.51 - - - DEC 0.67 - - - 01/01/94 – 01/02/94

0.00 - - -


0.00 - - -

01/28/94 0.28 01/29/94 – 01/31/94

0.00

02/01/94 – 02/03/94

0.00 - - -

02/04/94 – 02/05/94

0.56 - - -

02/06/94 0.00 02/07/94 – 02/08/94

1.14

02/09/94 – 02/16/94

0.00 - - -

02/17/94 0.47 - - - 02/18/94 1.01 02/19/94 0.10 02/20/94 0.97 02/21/94 0.28 - - - 02/22/94 – 02/28/94

0.00

MAR 0.00 - - -



California Coastal

Commission


Table A13. Rainfall and inundation during the 1992-1993 season. Inundation data from oblique aerial photograph (Bixby 2005). Based on the photographs and on rainfall pattern and amount, it is likely that WP and AP were continuously inundated for more than 30 days during the shaded period.




OCT 0.37 - - - NOV 0 - - - 12/01/92 - 12/06/92

0.0

12/07/92 - 12/08/92

4.33

12/11/92 0.12 12/18/92 0.11 12/28/92 - 12/31/92

0.92

01/01/93 - 01/02/93

0.34

01/06/93 - 01/08/93

3.30

01/11/93 - 01/19/93

4.06

01/31/93 0.39 02/01/93 – 02/09/93

1.21 - - -

02/10/93 - Large pond in oblique aerial photograph in vicinity of palm tree

Very large area at WP inundated Large ponds visible but much less obvious than at WP

02/11/93 – 02/18/93

0.00 - - -

02/19/93 – 02/28/93

1.93 - - -

03/01/93 - 03/25/93

0.0

03/26/93 - 03/31/93

1.61



California Coastal

Commission


Table 14. Rainfall and inundation during the 1991-1992 season. Inundation data from an oblique aerial photograph (Bixby 2005). Based on rainfall pattern and amount, WP and probably AP were continuously inundated for 15 - 30 days during the shaded period in February and in early March.




OCT 0.00 - - - NOV 0.06 - - - DEC 1.59 - - - 01/01/92 - 01/02/92 0.00

01/03/92 - 01/08/92 1.52

01/09/92 - 01/31/92 0.00

02/01/92 – 02/06/92 0.00 - - -

02/07/92 1.03 - - - 02/08/92 – 02/09/92 0.00 - - -

02/10/92 – 02/16/92 3.43 - - -

02/17/92 – 02/29/92 0.00 - - -

03/01/92 0.00 - - - 03/02/92 – 03/03/92 0.51 - - -

03/04/92 0.00 Not clear in oblique aerial photograph

Ponding apparent along flood control channel

Not clear in oblique aerial photograph

03/05/92 0.00 03/06/92 0.18 03/07/92 - 03//19/92 0.00

03/20/92 - 03/23/92 1.65

03/24/92 - 03/26/92 0.00

03/27/92 1.01 03/28/92 - 03/31/92 0.00



California Coastal

Commission


Table A15. Rainfall and inundation during the 1990-1991 season. Inundation data from a vertical aerial photograph (Homrighausen 2005). Based on rainfall pattern and amount, it is likely that WP and AP were continuously inundated for 7 - 14 days during March (shaded period).




OCT 0.00 - - - NOV 0.32 - - - DEC 0.08 - - - 01/01/91 – 01/02/91

0.00 - - -

01/03/91 – 01/05/91

1.04 - - -

01/06/91 – 01/09/91

0.00 - - -

01/10/91 0.35 - - - 01/11/91 – 01/13/91

0.00 - - -


0.00

- - -

02/01/91 – 02/27/91

0.00 - - -

02/28/91 1.38 - - - 03/01/91 – 03/02/91

1.48 - - -

03/03/91 – 03/13/91

0.18 - - -

03/14/91 0.32 - - - 03/15/91 – 03/18/91

0.00 - - -

03/19/91 – 03/21/91

1.35 - - -

03/22/91 – 03/24/91

0.00 - - -

03/25/91 – 03/28/91

1.71 - - -

03/29/91 – 03/31/91

0.00 - - -



California Coastal

Commission






OCT 0.51 - - - NOV 0.11 - - - DEC 0.00 - - - JAN 1.51 - - - 02/01/90 – 02/04/90

0.00 - - -

02/05/90 0.33 - - - 02/06/90 – 02/16/90

0.00 - - -

02/17/90 – 02/18/90

1.39 - - -

02/19/90 – 02/28/90

0.00 - - -

03/01/90 – 03/03/90

0.00 - - -

03/04/90 – 03/05/90

0.04 - - -

03/06/90 – 03/10/90

0.00 - - -

03/11/90 – 03/12/90

0.08 - - -

03/13/90 – 03/14/90

0.00 - - -


0.00 - - -



California Coastal

Commission






OCT 0.00 - - - NOV 0.69 - - - 12/01/88 – 12/15/88

0.00 - - -

12/16/88 – 12/23/88

0.97 - - -

12/24/88 0.00 - - - 12/25/88 1.20 - - - 12/26/88 – 12/31/88

0.00 - - -

12/27/88 – 12/31/88

0.00 - - -

01/01/89 – 01/29/89

0.45 - - -

01/30/89 0.00 No ponds visible No ponds visible No ponds visible 01/31/89 0.00 - - - FEB 0.76 - - - MAR 0.62 - - -



California Coastal

Commission






OCT 0.48 - - - NOV 1.30 - - - DEC 1.16 - - - 01/01/88 – 01/03/88

0.30 - - -

01/04/88 - 01/16/88

0.00 - - -

01/17/88 - 01/18/88

1.27 - - -

01/18/88 – 01/23/88

0.00 - - -


0.00 - - -

FEB 0.67 - - - MAR 0.27 - - -



California Coastal

Commission






OCT 0.10 - - - NOV 0.64 - - - DEC 0.45 - - - 01/01/87 – 01/03/87

0.00 - - -

01/04/87 – 01/07/87

1.57

- - -

01/08/87 0.00 - - - 01/09/87 0.00 No ponds visible- No ponds visible No ponds visible 01/10/87 – 01/20/87

0.00 - - -


0.04 - - -

FEB 0.79 - - - MAR 0.50

- - -



California Coastal

Commission


Table A20. Rainfall and inundation during the 1985-1986 season. Inundation data from a vertical aerial photograph (Homrighausen 2005). Based on rainfall pattern and amount, it is likely that WP and AP were continuously inundated for 15 - 30 days during the shaded period of February and March.




OCT 0.03 - - - 11/01/85 – 11/10/85

0.00 - - -

11/11/85 – 11/12/85

0.79 - - -

11/13/85 – 11/24/85

0.00 - - -

11/25/85 0.83 - - - 11/26/85 – 11/28/85

0.00 - - -

11/29/85 – 11/30/85

1.47 - - -

DEC 0.34 - - - 01/01/86 - 01/07/86

0.43

01/08/86 - 01/29/86

0.00

01/30/86 - 01/31/86

0.70

02/01/86 0.53 - - - 02/02/86 – 02/07/86

0.00 - - -

02/08/86 0.41 - - - 02/09/86 – 02/12/86

0.00 - - -

02/13/86 – 02/16/86

3.01 - - -

02/17/86 - 02/18/86

0.00

02/19/86 - 02/20/86

0.07

02/20/86 – 02/28/86

0.00 - - -

03/01/86 – 03/08/86

0.05 - - -

03/09/86 – 03/18/86

2.60

03/19/86 0.00 Ponded Large Pond Large Pond 03/20/86 – 03/31/86

0.00



California Coastal

Commission


APPENDIX B.

Tables B1 – B27: Photographic evidence of ponding, and rainfall data for the period 1958 – 1985 with LSA’s narrative interpretation (from Homrighausen, 2005). Shading and comments added.



California Coastal

Commission


Table B1: Rainfall and Inundation during the 1958–1959 Rainfall Season

Date Rainfall (inches) WP AP

Oct 25 1.35 Nov 12 0.02 Dec 0.00 Jan 6 0.71 Jan 17 photo Definitely no inundation in photo Definitely no inundation in photo Feb 7–12 0.61 Feb 16–17 1.14 Feb 19 0.06 Feb 21–22 1.00 Mar 0.00 Mar 24 Photo Obscured Probable inundation observed in

photo; does not match with rainfall data preceding date of photo

Apr 26 0.66 Total 5.55 The only large concentration of rain (2.2 inches) fell over a period of seven days, following a very dry fall and early winter. Photo evidence of inundation one month after this concentration is likely an indication of damp soil rather than inundation. Based on Dixon analysis of similar low rainfall years, inundation for more than 14 days is unlikely in both the WP and AP. JDD Comment: Based on rainfall pattern and amount, it is unlikely that topographic depressions were continuously inundated for long duration this season.



California Coastal

Commission




Oct 0.00 Nov 2 0.05 Dec 8–9 0.12 Dec 21 0.36 Dec 24–25 1.43 Jan 10–12 0.92 Jan 15 0.99 Jan 26 0.13 Feb 2 1.09 Feb 8–9 0.45 Feb 29 0.81 Mar 2 0.02 Mar 29 0.18 Apr 24 0.10 Apr 27 1.20 May 4 00.04 May 7 Photo Definitely no inundation Definitely no inundation Total 7.89 Concentrated rain events were relatively light and separated by at least two weeks in most cases. Photo provides evidence that there was no inundation 10 days after the last significant rain of the season. Therefore, inundation in both the WP and AP areas is unlikely. JDD Comment: Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for long duration during and after the shaded period in January. Following 1.79 inches of rainfall in the last 10 days of December, the 1.91 inches of rainfall from January 10-15 probably resulted in at least 7 days but less than 14 days of inundation.



California Coastal

Commission




Oct 0.00 Nov 4 0.21 Nov 6–7 0.62 Nov 13–14 0.26 Nov 27 0.52 Dec 2 0.09 Jan 25–27 0.64 Feb 0.00 Mar 15 0.16 Mar 25 0.18 Mar 28 0.03 Apr 23 0.02 Total 2.73 No photos were available for this season. The very low rainfall, spread throughout the season, likely did not result in inundation in either the WP or AP. JDD Comment: Based on rainfall pattern and amount, it is unlikely that topographic depressions were continuously inundated for long duration this season.



California Coastal

Commission




Oct 0.00 Nov 14–15 0.23 Nov 25–26 0.60 Dec 2–3 0.95 Dec 14–15 0.23 Jan 13 0.25 Jan 20–23 1.59 Jan 25 Photo Photo shows no inundation Inundation likely Feb 8–12 3.76 Feb 14 0.05 Feb 16 1.27 Feb 19–22 1.84 Mar 6 0.29 Mar 19 0.59 Mar 21 0.07 Mar 23 0.06 May 15–16 0.26 May 27 0.08 Total 12.52 The early part of the season was characterized by low, well-distributed rainfall. One heavy concentration of rain in a 15-day period (6.92 inches) likely produced inundation in the AP area. However, the photo shows no inundation in the WP two days after a significant rain (1.59 inches), and other photos of this period show no inundation in the WP area at any time. Therefore, it is likely that no depression existed. JDD Comment: Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for 15 - 30 days during the shaded period in February and March.



California Coastal

Commission




Oct 0.00 Nov 0.00 Dec 17 0.01 Jan 0.00 Feb 1–2 0.23 Feb 9–11 3.78 Feb 13 0.14 Mar 15 0.05 Mar 17–18 0.85 Mar 20 Photo Photo indicates no inundation Inundation likely Mar 23 0.48 Mar 28–29 0.90 Apr 8 0.01 Apr 15 0.08 Apr 17 0.11 Total 7.43 Extremely low rainfall early in the season, with one large event in mid-February, followed by a month of no rain, and then a series of smaller storms. It is likely that the AP area was inundated for some period but also likely that the inundation dissipated fairly rapidly, based on the well-documented dissipation rate of inundation following a similar amount of rain from 10/17 to 10/21 in 2004. Thus, inundation probably occurred, but the area actually inundated for more than 14 days was likely small. There is evidence that there was no inundated depression in the WP area during this period. JDD Comment: Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for 7 - 14 days during the shaded period in February and March.



California Coastal

Commission




Oct 16 0.28 Oct 21 0.01 Nov 7 0.43 Nov 12 0.01 Nov 16 0.39 Nov 20 1.44 Dec 9 0.01 Jan 19 0.17 Jan 21–22 0.51 Feb 0.00 Mar 2 0.09 Mar 13 0.04 Mar 23–24 0.79 Apr 1 0.55 Apr 19 0.02 May 5 0.05 Total 4.79 No photos available, but very low rainfall throughout the season likely resulted in no inundation in either area. JDD Comment: Based on rainfall pattern and amount, it is unlikely that topographic depressions were continuously inundated for long duration this season.



California Coastal

Commission




Oct 20 Photo Photo shows No Inundation Photo shows No Inundation Oct 28–29 0.10 Nov 9 0.43 Nov 11–12 0.18 Nov 17–18 0.60 Dec 19–21 0.40 Dec 23 0.02 Dec 27–29 0.97 Dec 31 0.02 Jan 7–8 0.20 Jan 24 0.24 Feb 6–7 0.22 Feb 10 Photo Photo shows no inundation Photo shows no inundation Mar 7 0.28 Mar 12–13 0.38 Mar 15 0.58 Mar 31 0.04 Apr 1 1.29 Apr 1 Photo Photo shows no inundation Photo clearly shows inundation

probably as a result of rain on the same day the photo was taken

Apr 2 0.14 Apr 3 1.00 Apr 4 0.67 Apr 8–10 1.47 Apr 13 0.11 Total 9.42 Rainfall very low through fall and winter, with one concentrated period of 4.69 inches in the last day of March and the first 10 days of April. Due to the lack of previous saturation and the lateness in the season, it is likely that percolation and evaporation dissipated the inundation in the AP area in approximately two weeks. Furthermore, there is no evidence of any depression in the WP area, even during a significant rain event that resulted in clear inundation in the AP area. JDD Comment: Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for 7 to 14 days during the shaded period in April.



California Coastal

Commission




Oct 0.00 Nov 15–18 2.82 Nov 22–23 1.83 Nov 25 0.40 Dec 9–10 0.91 Dec 12–16 0.90 Dec 29–31 1.12 Jan 30–31 0.94 Feb 2 0.23 Feb 6–7 0.93 Mar 2 0.06 Mar 25 0.25 Apr 0.00 May 9 0.07 Total 10.46 No photos available. Over 5 inches of rain fell in the last half of November, followed by 1.8 inches in early December and another inch at the end of December. Therefore, it is likely that some degree of inundation for two weeks took place in the AP area, at least in concentrated lower spots. The only other large storm occurred at the end of January. No depression in the WP area is visible in other photos from the decade, and inundation likely did not occur there. JDD Comment: Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for 15 - 30 days during the shaded period in November and December.



California Coastal

Commission




Oct 3 0.02 Nov 4 0.02 Nov 7–8 1.02 Nov 14 0.02 Nov 21 0.02 Dec 3–7 3.83 Jan 16 0.02 Jan 22–25 2.90 Jan 31 0.05 Feb 0.00 Mar 4–5 0.16 Mar 11 0.12 Mar 13–14 0.44 Mar 31– Apr2 0.85 Apr 5 0.27 Apr 11–12 0.40 Apr 19–22 1.21 Apr 24 0.32 Apr 29 0.05 Total 11.72 No photos. Two events were likely to cause short-term inundation in the AP area: 3.8 inches over four days in early December and 2.9 inches over four days in late January. All other significant rain events occurred earlier or later in the season. Based on the documented dissipation of inundation following three inches of rain in four days in the February 2004, the AP area was likely inundated for approximately two weeks following the major events in December or January, since these were approximately 45 days apart. The WP area showed no evidence of ponding during this decade. JDD Comment: Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for 7 to 14 days during and after the shaded periods in December and January.



California Coastal

Commission




Oct 0.00 Nov 19–22 1.99 Nov 28–29 0.18 Dec 1 0.25 Dec 8 0.06 Dec 19–20 0.83 Jan 2 0.02 Jan 11 0.10 Jan 27–28 0.23 Jan 31 0.11 Feb 10 0.05 Feb 13–14 0.22 Feb 17 0.01 Mar 8 1.97 Mar 14 0.06 Mar 17 0.07 Apr 2 0.59 May 12 0.02 Total 6.76 No photos. There were only two large events during the season; each was less than two inches and were separated by nearly four months. Inundation in either area is highly unlikely. JDD Comment: Based on rainfall pattern and amount, it is unlikely that topographic depressions were continuously inundated for long duration this season.



California Coastal

Commission




Oct 0.21 Nov 0.35 Dec 1.11 Jan 19–22 4.82 Jan 24–28 3.72 Feb 5.04 Mar 0.98 Apr 0.34 May 0.07 Total 17.93 No photos. Inundation is likely in many areas based on intense rainfall over a nine-day period in January. There is still no evidence of a depression in the WP area, but inundation is presumed. JDD Comment: February rainfall was as follows: 2/5-7 0.66”; 2/16 0.17”; 2/18-20 0.66”; 2/22-26 3.55”. Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for more than 30 days during the shaded period in January and February.



California Coastal

Commission




Sep 0.00 Oct 0.00 Oct 4 Photo Photo shows no inundation Photo shows no inundation Nov 7 1.58 Nov 10 0.03 Nov 16 0.03 Dec 2 0.02 Dec 9 0.04 Jan 10 0.86 Jan 12 0.41 Jan 16–17 0.74 Jan 24 0.02 Jan 31 Photo Photo indicates inundation unlikely Photo indicates inundation likely Feb 10–11 0.93 Mar 1–2 0.87 Mar 5 0.74 Total 6.27 Photos are available, but not definitive. Inundation for long periods is extremely unlikely based on the low amount and wide temporal distribution of rain. These data provide evidence that features identified in aerial photos as potential inundation are more likely darker soils, possibly indicative of somewhat higher soil moisture. JDD Comment: Based on rainfall pattern and amount, it is unlikely that topographic depressions were continuously inundated for long duration this season.



California Coastal

Commission




Sep 0.00 Oct 0.00 Nov 25–26 0.28 Nov 29–30 2.73 Dec 3 0.17 Dec 9 0.23 Dec 14 0.03 Dec 17–23 3.45 Jan 2 0.67 Jan 13–14 0.17 Feb 17 0.60 Feb 20 0.01 Feb 20 Photo Photo shows evidence of no

inundation Photo obscured

Feb 20 Photo Photo obscured No consensus on photo interpretation

Mar 13 0.19 Apr 5 Photo Photo shows evidence of no

inundation Photo shows probability of no inundation

Apr 14–15 0.52 May 7–8 0.29 May 27–28 0.10 Total 9.46 Timing of photos after the largest events in November and December is not helpful. If inundation occurred, it was likely following the late December storm period, since some saturation occurred prior in late November. Although photos do not corroborate this, inundation is assumed in the AP area. Still no evidence of a depression in the WP area. JDD Comment: Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for 7 to 14 days during the shaded period in December and January.



California Coastal

Commission




California Coastal

Commission



Oct 16 0.12 Nov 12 0.14 Dec 3–4 0.45 Dec 13 0.27 Dec 22–29 3.25 Jan 0.00 Feb 5 0.03 Feb 29 0.01 Mar 1 0.01 Apr 14 Photo Photo obscured Photo obscured Apr 20 0.08 Apr 29 Photo Indicates probable lack of

inundation Indicates probable lack of inundation

Apr 29 Photo Indicates probable inundation Indicates probable lack of inundation May 20 0.01 Total 4.37 Timing of photos is not very helpful. Based on very low rainfall total, length of time between large rain events in December, and photos in April, it is very unlikely that inundation was present in April. A probable lack of inundation as indicated by photo interpretation could be considered more conclusive. Some inundation likely occurred in late December, but due to very low rainfall before and after that date it is unlikely that inundation for longer than two weeks occurred in either area. This is the first indication of a depression in the WP area. JDD Comment: Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for 7 to 14 days during and after the shaded period in December.




California Coastal

Commission



Oct 4 0.01 Oct 19–20 0.14 Oct 25 0.01 Nov 8 0.01 Nov 11 0.35 Nov 14–17 3.06 Nov 24 Photo Photo indicates no inundation Photo indicates no inundation Dec 4–5 0.65 Dec 7–9 0.57 Jan 6 Photo Photo indicates no inundation Photo indicates inundation unlikely Jan 9–10 0.54 Jan 17 1.12 Jan 19 0.43 Jan 31 0.57 Feb 4–8 1.54 Feb 11–13 1.85 Feb 28 0.48 Mar 0.00 Apr 6–9 0.82 Apr 11–12 0.24 Apr 20 0.71 Apr 22 0.21 Apr 26 0.06 Total 13.37 Photo dates are very helpful in this season. Quite conclusive photo evidence that there was no inundation seven days after the end of a seven-day period in November that produced 3.41 inches of rain. The area was likely dry, and rain percolated quickly in the first part of the rainy season. Similar rainfall amounts occurred over a slightly longer period in the first half of February followed by under a half inch in late February and then a completely dry March. Based on this evidence, inundation for more than two weeks following rain events likely did not occur. JDD Comment: Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for 7 to 14 days during the shaded period in January and February.




California Coastal

Commission



Oct 9 0.05 Oct 17 0.01 Oct 23 0.07 Oct 26 Photo Photo indicates no inundation Photo indicates no inundation Nov 17–18 0.95 Nov 23 0.82 Dec 2 0.07 Dec 22 0.18 Jan 1 0.09 Jan 4–5 1.47 Jan 7–10 2.6 Jan 17 0.16 Jan 21 0.11 Jan 31 0.01 Feb 20 0.01 Mar 2–5 2.6 Mar 8–9 1.49 Mar 27 0.24 Apr 2 0.22 Total 9.47 Timing of photos is not helpful. Rain fell throughout the year, but there were 2 one-week periods (in early January and early March) when just over four inches of rain fell. Inundation may have occurred in both the AP and WP areas, but a determination of the length of the ponding would be very speculative. The existence of a depression in WP area has not been conclusively demonstrated at this time. JDD Comment: Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for 7 to 14 days during and after the shaded periods in January and March.




California Coastal

Commission



Oct 28–29 0.25 Nov 22 0.01 Dec 4–5 3.28 Dec 9 Photo Probable inundation Probable inundation Dec 28–29 0.80 Jan 31 0.14 Feb 3–4 0.99 Feb 9–10 0.63 Feb 17 Photo No inundation Probably no inundation Mar 5–6 0.63 Mar 8–11 0.97 Mar 14 0.10 Mar 17 0.07 Mar 22 0.32 Apr 1 0.02 Apr 6–7 0.78 Apr 15–16 0.24 Apr 25 0.05 Total 9.28 Timing of photos is helpful in this season. December 9 photo shows inundation in both areas four days after a major storm event. However, based on a similar situation with strong photographic evidence in 1972–1973, inundation probably did not last for two weeks. The rest of the season likely did not produce sufficient, concentrated rain to cause long-term inundation. JDD Comment: Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for 7 - 14 days during and after the shaded period in December.




California Coastal

Commission



Oct 7 0.07 Oct 11–12 0.18 Oct 31 0.05 Nov 27–29 0.27 Dec 13 0.04 Dec 21 0.05 Feb 4–8 1.26 Feb 10–11 0.65 Feb 21 Photo No Inundation No Inundation Mar 1–3 0.58 Mar 22 Photo No Inundation No Inundation Apr 4–5 0.68 Apr 12–13 0.34 Apr 21 0.04 Jun 4 Photo No Inundation No Inundation Total 4.21 February 21 photo was taken 10 days after the largest rainy period in the season (1.91 inches from February 4–11) confirming that no inundation occurred this year. JDD Comment: Based on rainfall pattern and amount, it is unlikely that topographic depressions were continuously inundated for long duration this season.




California Coastal

Commission



Oct 4 0.03 Nov 12 1.20 Nov 19 0.02 Dec 28 Photo No Inundation No Inundation Dec 31–Jan 1 0.36 Jan 3 0.62 Jan 6–7 1.37 Jan 21 0.27 Jan 27 0.09 Feb 24–25 0.37 Mar 14 Photo No Inundation No Inundation Mar 16–17 0.60 Mar 25–26 0.46 May 8–10 2.00 May 12–13 0.02 May 24 0.09 Total 7.50 Photos dates relative to rainfall are not very helpful here. Rainfall is relatively low this season with no large events except in May (2 inches), which would have dissipated fairly rapidly. Inundation is unlikely in either area. JDD Comment: Based on rainfall pattern and amount, it is unlikely that topographic depressions were continuously inundated for long duration this season.




California Coastal

Commission



Oct 0.00 Nov 0.00 Dec 18 0.26 Dec 26–29 2.13 Jan 4–7 2.07 Jan 10–11 1.59 Jan 15 1.22 Jan 17 0.73 Jan 19–20 0.64 Jan 31 0.04 Feb 5–10 4.36 Feb 13–14 1.37 Feb 27–28 0.18 Mar 1–6 3.85 Mar 10 0.2 Mar 12 0.21 Mar 23 0.23 Mar 31–Apr 2 0.64 Apr 5 0.14 Apr 16 0.61 Apr 25 0.01 Total 20.48 No photos. Very heavy rain in the early part of the season likely saturated soils, and large events in February and the first part of March likely resulted in long inundation in both the WP and AP areas. JDD Comment: Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for more than 30 days during the shaded winter period.




California Coastal

Commission



Sept 0.00 Oct 31 0.06 Nov 12 0.17 Nov 14 0.95 Dec 14 Photo No Inundation Probable Inundation Dec 17–19 0.99 Jan 5–6 1.42 Jan 10 0.26 Jan 15–16 0.96 Jan 19 0.15 Jan 31–Feb 3 3.21 Feb 14 0.72 Feb 21–23 0.57 Mar 1–2 0.08 Mar 13 0.03 Mar 11–17 0.25 Mar 19–21 0.60 Mar 27–29 1.75 Total 12.17 Given the relatively low amount of rainfall leading up to the photo date of December 14 and the length of time after the last rain, the indication of probable ponding in the AP is likely a “false positive” due to dark soils. The only large rainfall event at the end of January (3.21 inches) is well-separated from other major events, possibly allowing time for dissipation of any inundation that occurred, similar to the 1972–1973 season, when 3.06 inches dissipated within one week. However, in this case, there was considerably more rain prior to the 3.21 inches, which may have produced higher soil moisture and slowed percolation. Inundation in both areas may have occurred for more than two weeks but probably not significantly more. JDD Comment: Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for 15 - 30 days during and after the shaded period in January and February.




California Coastal

Commission


Date

Rainfall (inches

) WP AP Oct 20–21 0.20 Nov 8 0.46 Dec 21 0.09 Dec 25 0.18 Jan 7–14 4.17 Jan 18 0.06 Jan 28–30 2.17 Feb 14–19 5.89 Feb 21–22 0.85 Feb 25 Photo No Inundation Probable Inundation Mar 4 0.46 Mar 6–7 0.91 Mar 11 0.04 Mar 27 0.46 Apr 23 0.32 Apr 29–30 0.12 Total 16.38 Photo of February 25 conclusively shows no inundation in the WP area and suggests that inundation occurred in the AP area for a considerable time, likely two weeks or more, due to the large amount of rain (over 13 inches) that fell in a little over a month leading up to the photo date. JDD Comment: Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for more than 30 days during the shaded period in January and February.




California Coastal

Commission


Date

Rainfall (inches

) WP AP Oct–Nov 0.00 Dec 4–5 1.86 Jan 11–12 0.21 Jan 31 Photo No Inundation Probably No Inundation Jan 23 0.16 Jan 28–30 1.36 Feb 9 0.77 Feb 26 0.23 Mar 1–2 1.62 Mar 5–6 1.27 March 15 Photo Probable Inundation Probable Inundation Mar 20 0.27 Apr 18–19 0.22 May 27 0.01 Total 7.98 Inundation for two weeks unlikely due to low amount and relatively wide temporal distribution of rain. March 15 photo indication of probable inundation would be expected due to possible remnants of inundation after nine days and damp soil resulting from 2.9 inches of rain during the first week of the month. Likely at least AP area was ponded for 15 days or more in March. JDD Comment: Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for 15 - 30 days during the shaded period in March.




California Coastal

Commission



Oct 1–2 0.40 Oct 8 0.08 Oct 29 0.15 Nov 4 0.19 Nov 26–28 2.42 Dec 21 0.07 Dec 30–Jan 2 1.14 Jan 6 0.07 Jan 7 Photo No Inundation Probably No Inundation Jan 20–22 0.49 Jan 29 0.06 Feb 7–8 0.09 Feb 10–11 0.29 Mar 2–3 0.16 Mar 12 0.19 Mar 14–15 0.16 Mar 17–18 1.81 Mar 26–27 0.30 Mar 29–30 0.47 Apr 1–2 0.57 Apr 12 0.07 May 5 0.07 Total 9.64 No very large rain concentration. Any inundation from the largest event in November (2.42 inches) likely dissipated rapidly in the absence of additional rain for nearly a month. Several storms in the last half of March and first two days of April (3.31 inches) likely percolated and evaporated relatively quickly due to lateness in the season. JDD Comment: Based on rainfall pattern and amount, it is unlikely that topographic depressions were continuously inundated for long duration this season.




California Coastal

Commission


Date

Rainfall (inches

) WP AP Oct 0.21 Nov 2.28 Dec 0.84 Jan 2.06 Feb 3 0.57 Feb 6–7 0.47 Feb 13 0.06 Feb 19 Photo Probable Inundation Probable Inundation Feb 19 0.01 Feb 24–28 1.61 Mar 7 4.08 Mar 14 0.18 Mar 17–19 2.28 Mar 21 0.24 Mar 23–24 0.46 Mar 28 0.10 Apr 11 0.01 Apr 14 Photo Inundation Not Likely Inundation Not Likely Apr 15–30 1.79 May 1 0.32 May 11 Photo No Inundation Inundation Not Likely Total 17.57 February 19 photo may indicate actual inundation but more likely damp soil from moderate rains in November and January and lighter rain in first week of February. Extremely heavy rain in March (7.34 inches) likely produced extended inundation in both areas but seems to have dissipated by the middle of April. JDD Comment: Rainfall in January was as follows: 1/19 0.03”; 1/22-23 0.76”; 1/25 0.14; 1/27-29 1.13”. Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for 7 - 14 days during the shaded period in January and February and for more than 30 days during the shaded period in February and March.




California Coastal

Commission


Date

Rainfall (inches

) WP AP Sept 0.00 Oct 1 1.22 Oct 5 0.35 Oct 7 0.07 Nov 2 0.54 Nov 11–13 0.91 Nov 20–21 0.30 Nov 25 0.63 Dec 2 0.06 Dec 4 0.24 Dec 10 0.14 Dec 25–28 1.04 Jan 11 0.01 Jan 17 0.23 Mar 6 0.06 Apr 6 0.67 Apr 19 0.16 May 28 Photo No Inundation No Inundation Total 6.63 Photo date is not helpful for this season, but low rainfall, with only two events greater than one inch, likely produced no inundation in either area. JDD Comment: Based on rainfall pattern and amount, it is unlikely that topographic depressions were continuously inundated for long duration this season.




California Coastal

Commission



Sept 0.00 Oct 12 0.03 Oct 17 0.30 Nov 8 0.14 Nov 12 0.03 Nov 17 0.07 Nov 25 0.62 Dec 3 0.09 Dec 8–9 0.65 Dec 11 0.71 Dec 16 0.34 Dec 18–20 1.86 Dec 27–28 1.26 Jan 7–8 0.75 Jan 29 0.54 Feb 2 0.40 Feb 9 0.88 Feb 21 0.01 Mar 8 0.11 Mar 19 0.17 Mar 27 0.12 Apr 3 Photo No Inundation No Inundation Total 9.04 Relatively low rainfall year with wide temporal distribution. Total of just over three inches in the last half of December may have produced short-term inundation but likely dissipated before January 7 rain, which was followed by 20 days without rain. Long-term inundation not likely in either area. JDD Comment: Based on rainfall pattern and amount, it is likely that topographic depressions were continuously inundated for 15 - 30 days during and after the shaded period in December. The 1.70 inches of rain during December 8-16 probably saturated the soil, leading to long duration ponding as a result of the heavy rain in the last half of December.




California Coastal

Commission

Table B28: Summary of Inundation for Each Season

Inundation Likely WP AP

Season Y N Y N 58–59 x x 59–60 x x 60–61 x x 61–62 x x 62–63 x x* 63–64 x x 64–65 x x* 65–66 x x 66–67 x x* 67–68 x x 68–69 x x 69–70 x x 70–71 x x 71–72 x x 72–73 x x 73–74 x* x* 74–75 x x 75–76 x x 76–77 x x 77–78 x x 78–79 x* x* 79–80 x x 80–81 x x 81–82 x x 82–83 x x 83–84 x x 84–85 x x Subtotal 4 23 12 15 Summary From Dixon Analysis

11 10 11 10

Total 15 33 23 25 *Indicates that total length of likely inundation was approximately two weeks, which means that inundation remaining after two weeks was likely confined to small depressions. JDD Comment: Based on the data in Table B23 and the associated narrative, the “Yes” columns should have been checked for “80-81,” resulting in more than 14 days of continuous inundation during 13 years at AP and during 5 years at WP, as estimated by LSA. For the period 1985 - 2005, my current estimate (Table 1, above) is that continuous inundation for at least 7 days occurred at AP during 11 years and at WP during 12 years.